You've got a critical bug report. A user can't complete their purchase at checkout. You open Mixpanel, navigate to session replay, watch them click through the checkout flow... and then they get stuck. The frontend looks fine, but something's clearly broken. What failed on the backend? Was it a payment service timeout? A validation error?

Now you're digging through logs, checking APM dashboards, correlating timestamps, and trying to piece together what happened on the backend.

This is the gap between product analytics platforms with session replay features and purpose-built debugging tools.

TL;DR

Choose Multiplayer if: You need to resolve technical issues fast, with complete frontend + backend context in one place, and you need to improve your debugging workflows across multiple teams (e.g. Support → Engineering).

Choose Mixpanel if: You primarily need product analytics with session replay as a supplementary feature for understanding user behavior.

Key difference: Mixpanel shows you how users behave on your frontend, aggregating website performance metrics. Multiplayer shows how your system behaves, from user actions to backend traces, and how to fix a bug (or have your AI coding assistant do it for you).

Quick comparison

More resources:

• Multiplayer vs Mixpanel deep dive
• Multiplayer vs other tools

The real difference: frontend vs full stack

Mixpanel: product analytics platform with session replay bolted on

Mixpanel is a mature product analytics platform with core features such as: event tracking, funnels, cohort analysis, A/B testing. Session replays is an additional feature in this toolset to help understand user behavior and product metrics.

But when you need to debug a technical issue, you only get frontend data. Mixpanel has no backend data or observability tools integrations, which means:

• No visibility into API calls beyond the browser
• No distributed traces showing which services were involved
• No request/response content from your backend services
• No console messages or HTML source code

When debugging a production issue, you're forced to:

• Search through Mixpanel's session replays (frontend only)
• Switch to your observability platform and hunt through logs to find the right data
• Manually correlate timestamps across systems
• Piece together what happened without a unified view

Multiplayer: purpose-built for debugging

Multiplayer captures full stack session recordings by default. Every frontend action is automatically correlated with backend traces, logs, and request/response data, in a single, unified timeline.

When the checkout button fails, you see:

• The user's click
• The API request
• The backend trace showing which service failed
• The exact error message and stack trace
• Request/response content and headers from internal service calls

No hunting. No manual correlation. No tool switching. Everything you need to fix the bug is in one place.

Recording control: always-on vs choose-your-adventure

Mixpanel: Always-on recording via SDK

Mixpanel uses always-on recording through its SDK: you're recording and storing everything, whether you need it or not. This works for aggregate analytics, but creates friction for debugging:

• No granular control over when and which sessions to capture
• Can't easily capture specific user cohorts or error scenarios
• Limited to SDK installation (no browser extensions or widgets for end-users)

Multiplayer: record what you need, when you need it

Multiplayer offers three recording modes and three installation methods. It’s a choose-your-own-adventure approach that adapts to your teams’ workflows.

Recording modes:

• On-demand: Start/stop recording manually. Perfect for reproducing specific bugs.
• Continuous: Start/stop recording in the background, during your entire working session. Great for development and QA to automatically save sessions with errors and exceptions.
• Conditional: Silent capture of specific user cohorts or error conditions.

Installation methods:

• In-app widget: Let users report issues with replays attached automatically, directly from your app
• Browser extension: Quickly capture a bug, unexpected behavior, or new feature idea
• SDK / CLI Apps: Full integration for programmatic control

Real scenario: Your support team gets a vague bug description. They ask the end-user to record a full stack session replay through the in-app widget. Support is able to fully understand the problem and they can reproduce the issue in 30 seconds. It’s immediately clear what the next steps (or possible fixes) are.

Support workflows: serial handoffs vs parallel collaboration

Mixpanel: Built for product teams, not support workflows

Mixpanel's workflow is designed for product analytics:

• Track events and user properties
• Analyze funnels and retention
• View session replays as supplementary context
• Share reports and dashboards

For technical debugging, you're doing manual work:

1. Support searches and watches a session replay in Mixpanel
2. Support escalates to Engineering with partial context
3. Engineering opens observability tools to find backend data
4. Engineering searches for the right logs and traces
5. Multiple rounds of back-and-forth to gather full context

Multiplayer: complete context from the start

Multiplayer is built for parallel Support ↔ Engineering workflows:

Single, sharable timeline:

• Frontend screens, user actions, backend traces, logs, request/response data, and user feedback, all correlated automatically
• Support sees the user's experience; Engineering sees the technical root cause
• Both work from the same data, at the same time

Annotations and collaboration:

• Sketch directly on recordings
• Annotate any data point in the timeline
• Create interactive sandboxes for API integrations
• Link sessions directly to Zendesk, Intercom, or Jira tickets

What you actually get per session

Mixpanel captures:

• User clicks ✓
• Page navigations ✓
• DOM events ✓
• Network requests ✓

Multiplayer captures:

Everything Mixpanel captures, plus:

• Console messages ✓
• HTML source code ✓
• Correlated backend logs and traces (any observability platform, unsampled) ✓
• Backend errors ✓
• Full request/response content and headers (including from internal service calls) ✓
• User feedback integrated in the timeline ✓
• Service and dependency maps ✓

Integration and deployment: flexibility matters

Mixpanel:

• SDK installation only
• SaaS deployment only
• MCP server for interrogating product data (not debugging)

Multiplayer:

• Multiple installation methods (extension, widget, SDK)
• SaaS or self-hosted deployment
• Works with any observability platform, language, framework, architecture
• MCP server feeds complete context to your IDE or AI tool

For teams with compliance requirements: Mixpanel's SaaS-only model can be a dealbreaker. Multiplayer's self-hosted option keeps sensitive data in your infrastructure.

For AI-forward teams: Mixpanel's MCP server is optimized for product data analysis: understanding user behavior and product metrics. Multiplayer's MCP server feeds complete debugging context (frontend + unsampled backend + annotations + full request/response data) directly to Claude, Cursor, or your AI tool of choice. Ask "why did this checkout fail?" and get answers grounded in complete session data, not just frontend clicks.

Which tool should you choose

Choose Multiplayer if:

• You need to fix bugs and resolve technical issues fast
• You want complete backend visibility alongside frontend data
• Your support team regularly escalates issues to engineering
• You need full request/response content from internal services
• You want flexible recording modes and installation options
• You have compliance requirements that need self-hosting
• You want AI-native debugging workflows with complete context

Choose Mixpanel if:

• Your primary goal is product analytics (funnels, cohorts, retention, A/B testing)
• Product and UX teams are your main users
• Session replay is a supplementary feature for understanding user behavior
• You don't need backend debugging data
• You're comfortable managing separate tools for analytics and debugging

Consider both if:

• You're a large organization where product analytics and technical debugging are handled by separate teams with separate objectives

The bottom line

Mixpanel is a powerful product analytics platform with comprehensive event tracking and analysis capabilities. Session replay is an add-on feature designed for understanding user behavior, not for debugging technical issues across your full stack.

Multiplayer is purpose-built for debugging. Full-stack session recordings give you frontend and backend context, automatically correlated in a single timeline. It's session replay designed for the reality of modern distributed systems, where you need complete technical context to fix issues fast.

You've got a bug report from a frustrated user. You open PostHog, search through all the session replays to find the right one, watch the frontend interaction, and see where they got stuck. But you can't see what failed on the backend. Was it a timeout? A validation error? A service dependency issue?

Now you're digging through logs, checking APM dashboards, correlating timestamps, and trying to piece together what happened on the backend.

This is the gap between product analytics platforms with session replay features and purpose-built debugging tools.

TL;DR

Choose Multiplayer if: You need to resolve technical issues fast, with complete frontend + backend context in one place, and you need to improve your debugging workflows across multiple teams (e.g. Support → Engineering).

Choose PostHog if: You primarily need product analytics with session replay as a supplementary feature for understanding user behavior.

Key difference: PostHog is a product analytics platform with frontend-only session replay. Multiplayer is purpose-built for debugging with full-stack session recordings, from user actions to backend traces, showing you how to fix a bug (or have your AI coding assistant do it for you).

Quick comparison

More resources:

• Multiplayer vs PostHog deep dive
• Multiplayer vs other tools

The real difference: product analytics vs debugging tool

PostHog: Analytics platform with session replay

PostHog is a comprehensive product analytics platform. Session replay is one feature among many (feature flags, A/B testing, surveys, product analytics). For understanding user behavior, funnel analysis, and product decisions, this works well.

But when you need to debug a technical issue, you only get frontend data. PostHog has no backend data or observability integrations, which means:

• No visibility into API calls beyond the browser
• No distributed traces showing which services were involved
• No request/response content from your backend services

When debugging a production issue, you're forced to:

• Search through PostHog to find the right session replay (frontend only)
• Switch to your observability platform for backend data
• Manually correlate timestamps across systems
• Piece together what happened without a unified view

Multiplayer: Purpose-built for debugging

Multiplayer is focused on resolving technical issues. Full-stack session recordings capture everything you need in a single timeline:

• The user's frontend actions
• The API requests
• Backend traces showing which services were called
• Request/response content and headers from internal service calls
• Error messages and stack traces
• User feedback

No searching through hundreds of sessions. No tool switching. No manual correlation.

Recording control: analytics-first vs choose-your-adventure

PostHog: conditional recording

PostHog offers always-on recording (via SDK) based on conditions you can customize. This works for product analytics where you want to capture broad user behavior:

• No granular control over when and which sessions to capture
• Limited to SDK installation (no browser extensions or widgets for end-users)

Multiplayer: record what you need, when you need it

Multiplayer offers three recording modes and three installation methods. It’s a choose-your-own-adventure approach that adapts to your teams’ workflows.

Recording modes:

• On-demand: Start/stop recording manually. Perfect for reproducing specific bugs.
• Continuous: Start/stop recording in the background during your entire working session. Great for development and QA to automatically save sessions with errors and exceptions.
• Conditional: Silent capture of specific user cohorts or error conditions.

Installation methods:

• In-app widget: Let users report issues with replays attached automatically, directly from your app
• Browser extension: Quickly capture a bug, unexpected behavior, or new feature idea
• SDK / CLI Apps: Full integration for programmatic control

Real scenario: Your support team gets a vague bug description. They ask the end-user to record a full stack session replay through the in-app widget. Support is able to fully understand the problem and they can reproduce the issue in 30 seconds. It’s immediately clear what the next steps (or possible fixes) are.

Support workflows: serial handoffs vs parallel collaboration

PostHog: Built for product teams, adapted for support

PostHog's workflow is designed for product analytics:

• Search through session replays to find the relevant one
• Share session links with your team
• View frontend behavior
• Build dashboards and funnels

But for technical debugging, this creates serial handoffs:

1. Support searches and watches the replay (frontend only)
2. Support escalates to Engineering with partial context
3. Engineering opens observability tools to find backend data
4. Engineering searches for the right logs and traces
5. Multiple rounds of back-and-forth to gather full context

Multiplayer: complete context from the start

Multiplayer is built for parallel Support ↔ Engineering workflows:

Single, sharable timeline:

• Frontend screens, user actions, backend traces, logs, request/response data, and user feedback, all correlated automatically
• Support sees the user's experience; Engineering sees the technical root cause
• Both work from the same data, at the same time

Annotations and collaboration:

• Sketch directly on recordings
• Annotate any data point in the timeline
• Create interactive sandboxes for API integrations
• Link sessions directly to Zendesk, Intercom, or Jira tickets

What you actually get per session

PostHog captures:

• User clicks ✓
• Page navigations ✓
• DOM events ✓
• Console messages ✓
• Network requests ✓
• Backend errors (requires PostHog backend instrumentation—vendor lock-in) ✓

Multiplayer captures:

Everything PostHog captures, plus:

• Correlated backend logs and traces (any observability platform, unsampled) ✓
• Backend errors (no vendor lock-in) ✓
• Full request/response content and headers (including from internal service calls) ✓
• User feedback integrated in the timeline ✓
• Service and dependency maps ✓

Which tool should you choose

Choose Multiplayer if:

• You need to fix bugs and resolve technical issues fast
• You want complete backend visibility alongside frontend data
• Your support team regularly escalates issues to engineering
• You need full request/response content from internal services
• You want flexible recording modes and installation options
• You want AI-native debugging workflows with complete context

Choose PostHog if:

• Your primary goal is product analytics (funnels, feature flags, A/B testing, surveys)
• Product and UX teams are your main users
• Session replay is a supplementary feature for understanding user behavior
• You don't need backend debugging data
• You're comfortable managing separate tools for analytics and debugging

Consider both if:

• You're a large organization where product analytics and technical debugging are handled by separate teams with separate objectives

The bottom line

PostHog is a powerful product analytics platform with many valuable features. Session replay is one tool among many, designed for understanding user behavior and product performance, not for debugging technical issues across your full stack.

Multiplayer is purpose-built for debugging. Full-stack session recordings give you frontend and backend context, automatically correlated in a single timeline. It's session replay designed for the reality of modern distributed systems, where you need complete technical context to fix issues fast.

You've got a critical bug report. A user can't complete checkout. You open Fullstory, watch the session replay, see them click the checkout button... and then what? The frontend looks fine, but something's clearly broken. Now you're digging through logs, checking APM dashboards, correlating timestamps, and trying to piece together what happened on the backend.

This is the gap between user analytics tools and debugging tools.

TL;DR

Choose Multiplayer if: You need to resolve technical issues fast, with full frontend + backend context in one place, and you need to improve your debugging workflows across multiple teams (e.g. Support → Engineering).

Choose Fullstory if: You primarily need behavioral analytics for product and UX decisions.

Key difference: Fullstory shows you how users behave on your website, aggregating performance metrics. Multiplayer shows how your system behaves, from user actions to backend traces, and how to fix a bug (or have your AI coding assistant do it for you).

Quick comparison

More resources:

• Multiplayer vs Fullstory deep dive
• Multiplayer vs other tools

The real difference: frontend vs full stack

Fullstory (or half the story?)

Fullstory captures what happens in the browser: clicks, page loads, DOM events. For understanding user flows and UX patterns, this is valuable. But when you're debugging a technical issue, you're missing the critical half: what happened in your backend.

When an API call fails, a database query times out, or a microservice throws an error, you're forced to:

• Switch to your observability platform
• Manually correlate timestamps
• Hunt through logs to find the right data
• Piece together context across multiple tools

Multiplayer: the actual full story

Multiplayer captures full stack session recordings by default. Every frontend action is automatically correlated with backend traces, logs, and request/response data, in a single, unified timeline.

When that checkout button fails, you see:

• The user's click
• The API request
• The backend trace showing which service failed
• The exact error message and stack trace
• Request/response content and headers from internal service calls

No hunting. No manual correlation. No tool switching. Everything you need to fix the bug is in one place.

Real scenario: A user reports "payment failed" but your logs show a 200 response. With Multiplayer, you see: the button click, the API call to your payment service, the upstream call to Stripe, the 429 rate limit error from Stripe, and the incorrectly handled error response your service returned as a 200.

Recording control: always-on vs choose-your-adventure

Fullstory: Always-on recording via SDK

Fullstory uses always-on recording through its SDK: you're recording and storing everything, whether you need it or not. This works fine for aggregate analytics, but creates friction for debugging:

• No granular control over when and which sessions to capture
• Can't easily capture specific user cohorts or error scenarios
• Limited to SDK installation (no browser extensions or widgets for end-users)

Multiplayer: record what you need, when you need it

Multiplayer offers three recording modes and three installation methods. It’s a choose-your-own-adventure approach that adapts to your teams’ workflows.

Recording modes:

• On-demand: Start/stop recording manually. Perfect for reproducing specific bugs.
• Continuous: Start/stop recording in the background during your entire working session. Great for development and QA to automatically save sessions with errors and exceptions.
• Conditional: Silent capture of specific user cohorts or error conditions.

Installation methods:

• In-app widget: Let users report issues with replays attached automatically, directly from your app
• Browser extension: Quickly capture a bug, unexpected behavior, or new feature idea
• SDK / CLI Apps: Full integration for programmatic control

Real scenario: Your support team gets a vague bug description. They ask the end-user to record a full stack session replay through the in-app widget. Support is able to fully understand the problem and they can reproduce the issue in 30 seconds. It’s immediately clear what the next steps (or possible fixes) are.

Support workflows: serial handoffs vs parallel collaboration

Fullstory: built for analysts, not debugging teams

Fullstory's collaboration features are designed for PM and UX teams reviewing sessions asynchronously:

• Share session links
• Add highlights and notes
• Build funnels and dashboards

But for technical debugging, this creates serial handoffs:

1. Support searches and watches the replay (frontend only)
2. Support escalates to Engineering with partial context
3. Engineering opens observability tools to find backend data
4. Engineering asks follow-up questions
5. Support provides more details
6. Repeat until enough context is gathered

Multiplayer: complete context from the start

Multiplayer is built for parallel Support ↔ Engineering workflows:

Single, sharable timeline:

• Frontend screens, user actions, backend traces, logs, request/response data, and user feedback, all correlated automatically
• Support sees the user's experience; Engineering sees the technical root cause
• Both work from the same data, at the same time

Annotations and collaboration:

• Sketch directly on recordings
• Annotate any data point in the timeline
• Create interactive sandboxes for API integrations
• Link sessions directly to Zendesk, Intercom, or Jira tickets

What you actually get per session

Fullstory captures:

• User clicks ✓
• Page navigations ✓
• DOM events ✓
• Console messages (browser only) ✓
• Network requests (paid plans only) ✓

Multiplayer captures:

Everything Fullstory captures, plus:

• Correlated backend logs and traces (any observability platform, unsampled) ✓
• Backend errors ✓
• Full request/response content and headers (including from internal service calls) ✓
• User feedback integrated in the timeline ✓
• Service and dependency maps ✓

Integration and deployment: flexibility matters

Fullstory:

• SDK installation only
• SaaS deployment only
• Mobile support is a paid add-on
• No backend visibility or observability integrations
• No support for AI coding workflows

Multiplayer:

• Web and mobile support out of the box
• Multiple installation methods (extension, widget, SDK)
• SaaS or self-hosted deployment
• Works with any observability platform (Datadog, New Relic, Grafana, etc.), language, framework, and architecture
• MCP server for AI-native debugging in your IDE or AI assistant

For teams with compliance requirements: Fullstory's SaaS-only model can be a dealbreaker. Multiplayer's self-hosted option keeps sensitive data in your infrastructure.

For AI-forward teams: Multiplayer's MCP server feeds complete session context (frontend + backend + annotations) directly to Claude, Cursor, or your AI tool of choice. Ask "why did this checkout fail?" and get answers grounded in the actual session data.

Which tool should you choose

Choose Multiplayer if:

• You need to fix bugs and resolve technical issues fast
• Your support team regularly escalates issues to engineering
• You need backend visibility alongside frontend data
• You want flexible recording modes (not just always-on)
• You need to correlate frontend and backend data without manual work
• You have compliance requirements that need self-hosting
• You want AI-native debugging workflows

Choose Fullstory if:

• Your primary goal is user analytics and UX optimization
• PM and design teams are your main users
• You don't need backend data integrated with session replays
• Always-on, frontend-only recording meets your needs

Consider both if:

• You're a large organization where user analytics and technical debugging are handled by separate teams with separate objectives

The bottom line

Fullstory is a powerful behavioral analytics platform. But if you're using it to debug technical issues, you're working with one hand tied behind your back. You're missing backend data, manually correlating across tools, and creating slow handoffs between support and engineering.

Multiplayer gives you the complete picture: frontend and backend, correlated automatically, in a single timeline, with purpose-built collaboration for technical teams. It's session replay designed for the reality of modern distributed systems.

Whiteboarding tools are indispensable in system design for visually conveying concepts, ideas, and rough plans. They tap into our natural preference for visual learning. Most people, after all, agree that "a picture is worth a thousand words."

But static whiteboarding tools lack the crucial element that makes feedback truly actionable: context.

That's why we evolved our Sketches feature into Annotations, a way to draw, write, and comment directly on top of full-stack session recordings. Now, instead of sketching ideas in isolation, teams can mark up actual user sessions, highlighting specific UI elements, API calls, and backend traces that need attention.

Why Annotate Session Recordings?

Multiplayer automatically captures everything happening in your application: frontend screens, user actions, backend traces, metrics, logs, and full request/response content and headers. But when something goes wrong or needs improvement, pointing at the exact moment and explaining what should change requires more than just text.

Annotations let you:

• Draw directly on the replay with shapes, arrows, and highlights to mark problem areas or desired changes
• Add on-screen text to explain intended behavior or specify new UI copy
• Attach timestamp notes to clarify reproduction steps, requirements, or design intentions
• Reference full-stack context by annotating user clicks, API calls, traces, and spans directly

Because Multiplayer auto-correlates frontend and backend data, your annotations aren't just surface-level markup: they're tied to the actual technical events that need investigation or modification.

How Support Teams Use Annotations

1. Clarifying Bug Reports

When a customer reports confusing behavior, support teams can create an annotated recording that shows:

• Red circles highlighting where the UI behaved unexpectedly
• Arrows pointing to the button that should have appeared
• Text annotations explaining what the customer expected to see
• Timestamp notes marking the exact API call that returned the wrong data

This annotated session becomes a complete bug report that engineering can understand immediately. No back-and-forth required.

2. Documenting Reproduction Steps

Instead of writing lengthy reproduction steps like "Click the dashboard, then filters, then date range, then apply," support can:

• Record themselves reproducing the issue once
• Add timestamp notes at key moments: "User opens filters here," "Selects invalid date range," "Error appears at 0:45"
• Highlight the error message in red with a note: "This message is confusing. We should clarify valid date format"

Engineering gets a visual, interactive guide to the problem with full backend context included.

3. Collecting Feature Requests with Visual Context

When customers suggest improvements, support can annotate recordings to show:

• Green highlights around areas customers want enhanced
• Sketched mockups showing proposed layouts
• Text annotations with customer quotes about desired behavior

How Engineering Teams Use Annotations

1. Reviewing PRs with Visual Feedback

During code review, engineers can record themselves testing a new feature and add annotations:

• Yellow boxes around UI elements that need spacing adjustments
• Arrows indicating where loading states should appear
• Text specifying exact pixel values or color codes
• Timestamp notes on API calls: "This endpoint takes 2.3s, should we add caching?"

The developer receives actionable visual feedback tied to actual runtime behavior, not abstract suggestions.

2. Debugging with Annotated Evidence

When investigating production issues, engineers can:

• Record a session where the bug occurs
• Circle the problematic UI element in red
• Add arrows pointing from the frontend error to the failing API trace
• Annotate the trace span with notes: "This database query times out under load"

This creates a self-documenting investigation that other team members can follow.

3. Planning Refactors with Visual Context

Before refactoring complex flows, teams can:

• Record the current user journey
• Use different colored annotations to map out different concerns (blue for performance, purple for UX improvements, orange for tech debt)
• Add timestamp notes explaining why each step exists
• Sketch the proposed new flow directly on top of the recording
• Reference specific API calls and traces that will be affected

4. Onboarding New Engineers

Senior engineers can create annotated recordings that serve as interactive documentation:

• Record a typical user flow
• Add green annotations explaining key architectural decisions
• Highlight important code paths with timestamp notes
• Mark API boundaries and service interactions
• Sketch out related system components and their relationships

New team members can pause, replay, and reference the full-stack context as they learn.

Most modern software systems are distributed systems. Designing and maintaining a distributed system, however, isn't easy. There are so many areas to master: communication, security, reliability, concurrency, and, crucially, observability and debugging.

When things go wrong (and they will as we've seen recently and repeatedly), you need to understand what happened across your entire stack.

Here are six best practices to get you started:

(1) Design for failure (and debuggability)

Failure is inevitable in distributed systems. Most of us are familiar with the 8 fallacies of distributed computing, those optimistic assumptions that don't hold in the real world. Switches go down. Garbage collection pauses make leaders "disappear." Socket writes appear to succeed but have actually failed on some machines. A slow disk drive on one machine causes a communication protocol in the whole cluster to crawl.

Back in 2009, Google fellow Jeff Dean cataloged the "Joys of Real Hardware," noting that in a typical year, a cluster will experience around 20 rack failures, 8 network maintenances, and at least one PDU failure.

Fast forward to 2025, and outages remain a fact of life:

• November 18, 2025 - A bug in Cloudflare's Bot Management system caused widespread disruption across many web services
• October 20, 2025 - An AWS disruption in the US-East-1 region affected thousands of applications
• April 28, 2025 - A power-grid collapse in Spain and Portugal disrupted electric, telecommunication, and transport services across the Iberian Peninsula

The lesson? Design your system assuming it will fail, not hoping it won't. Build in graceful degradation, redundancy, and fault tolerance from the start.

But resilience isn't enough. You also need debuggability. When (not if) failures occur, your team needs answers fast:

• What triggered the failure? The user action, the API call, the specific request that started the cascade
• How did it propagate? Which services were involved, what data was passed between them, where did things go wrong
• Why did it happen? The root cause. Whether in your backend logic, database queries, or infrastructure layer

This requires capturing complete technical context, not just high-level signals. Aggregate metrics and sampled traces tell you something is wrong. Full context tells you exactly what went wrong and why.

Traditional monitoring gives you: "The system is slow."

What you actually need: "This specific user's checkout failed because the payment service timed out waiting for the inventory service, which was blocked on a slow database query."

The difference between these two statements is the difference between hours of investigation and minutes to resolution.

(2) Choose your consistency and availability models

Generally, in a distributed system, locks are impractical to implement and difficult to scale. As a result, you'll need to make trade-offs between the consistency and availability of data. In many cases, availability can be prioritized and consistency guarantees weakened to eventual consistency, with data structures such as CRDTs (Conflict-free Replicated Data Types).

It's also important to note that most modern systems use different models for different data. User profile updates might be eventually consistent, while financial transactions require strong consistency. Design your system with these nuances in mind rather than applying one model everywhere.

A few more considerations:

Pay attention to data consistency: When researching which consistency model is appropriate for your system (and how to design it to handle conflicts and inconsistencies), review foundational resources like The Byzantine Generals Problem and the Raft Consensus Algorithm. Understanding these concepts helps you reason about what guarantees your system can actually provide and what it can't.

Strive for at least partial availability: You want the ability to return some results even when parts of your system are failing. The CAP theorem (Consistency, Availability, and Partition Tolerance) is well-suited for critiquing a distributed system design and understanding what trade-offs need to be made. Remember: out of C, A, and P, you can't choose CA. Network partitions will happen, so you're really choosing between consistency and availability when partitions occur.

(3) Build on a solid foundation from the start

Whether you're a pre-seed startup working on your first product, or an enterprise company releasing a new feature, you want to assume success for your project.

This means choosing the technologies, architecture, and protocols that will best serve your final product and set you up for scale. A little work upfront in these areas will lead to more speed down the line:

Security: A zero-trust architecture is the standard: assume breaches will happen and design accordingly to minimize your blast radius.

Containers: Some may still consider containers an advanced technique, but modern container runtimes have matured significantly, making containerization a default choice

Orchestration: Reduce the operational overhead and automate many of the tasks involved in managing containerized applications. Kubernetes has become the de facto standard, but for smaller teams, managed container services (AWS ECS/Fargate, Google Cloud Run, Azure Container Apps) offer simpler alternatives without sacrificing scalability.

Infrastructure as code: Define infrastructure resources in a consistent and repeatable way, reducing the risk of configuration errors and ensuring that infrastructure is always in a known state. Tools like Terraform, Pulumi, and AWS CDK make infrastructure changes reviewable, testable, and version-controlled.

Standard communication protocols: REST, gRPC, GraphQL, and other well-established protocols simplify communication between different components and improve compatibility and interoperability. Choose protocols that match your use case: REST for simplicity, gRPC for performance, GraphQL for flexible client needs.

Observability from day one: Don't treat logging, metrics, and tracing as something you add later. Build observability into your system from the start, including structured logging, distributed tracing, and comprehensive session recording. When issues arise (and they will), having this context already in place is the difference between quick resolution and prolonged outages.

(4) Minimize dependencies

If the goal is to have a system that is resilient, scalable, and fault-tolerant, then you need to consider reducing dependencies with a combination of architectural, infrastructure, and communication patterns.

Service Decomposition: Each service should be responsible for a specific business capability, and they should communicate with each other using well-defined APIs. Start with a well-modularized monolith and extract services only when you have clear reasons (team autonomy, different scaling needs, technology requirements).

Organization of code: Choosing between a monorepo or polyrepo depends on your project requirements. Monorepos excel at atomic changes across services and shared tooling, while polyrepos provide stronger boundaries and independent versioning. Modern monorepo tools (Nx, Turborepo, Bazel) have made the monorepo approach increasingly viable even at large scale.

Service Mesh: A dedicated infrastructure layer for managing service-to-service communication provides a uniform way of handling traffic between services, including routing, load balancing, service discovery, and fault tolerance. Service meshes like Istio, Linkerd, and Consul add complexity (so evaluate carefully whether you actually need one!) but solve real problems at scale.

Asynchronous Communication: By using patterns like message queues and event streams, you can decouple services from one another. This reduces cascading failures: if one service is down, messages queue up rather than causing immediate failures. Tools like Kafka, RabbitMQ, and cloud-native options (AWS SQS, Google Pub/Sub) enable this decoupling.

Circuit breakers and timeouts: Implement patterns that prevent cascading failures. When a downstream service is struggling, circuit breakers stop sending it traffic, giving it time to recover. Proper timeouts prevent one slow service from tying up resources across your entire system.

(5) Monitor and measure system performance

In a distributed system, it can be difficult to identify the root cause of performance issues, especially when there are multiple systems involved.

Any developer can attest that "it's slow" is and will be one of the hardest problems you'll ever debug!

In recent years we've seen a shift from traditional Application Performance Monitoring (APM) to modern observability practices, as the need to identify and understand "unknown unknowns" becomes more critical.

Traditional APM tools excel at answering questions you already know to ask: "Is the database slow?", "What's the error rate?", etc. But struggle with the unexpected, hard-to-reproduce and understand issues that plague distributed systems. That's why modern observability focuses on capturing complete context about system behavior.

Rather than just collecting aggregate metrics and sampled traces, comprehensive observability tools capture:

• Complete request traces across your entire distributed system, not just statistical samples
• Full session context showing what users actually did, not just backend telemetry
• Detailed interaction data including request/response payloads, database queries, and service call chains
• Correlated frontend and backend behavior so you can see how user actions translate to system load

This approach shifts focus from reactive monitoring ("the system is down, what happened?") to proactive understanding ("why is this specific user experiencing slowness?"). Full stack session recordings exemplify this shift: they capture complete user journeys along with all the technical context needed to understand exactly what happened.

(6) Design dev-first debugging workflows

Most debugging workflows evolved accidentally. Support collects what they can from end-users. Escalation specialists add a few notes. Engineers get a ticket with partial logs, a vague user description, and maybe a screenshot or video recording.
Then the real work begins: clarifying, reproducing, correlating, guessing.

This is backward.

In modern distributed systems, developers are your most expensive, highest-leverage resource. Every minute they spend asking for missing context, grepping through log files, or reconstructing what happened is a minute they’re not fixing the problem, improving the system, or shipping value.

Dev-first debugging flips this model. Instead of assembling context, your tools should capture everything by default:

• Exact user actions and UI state
• Correlated backend traces, logs, and events
• Request/response bodies and headers
• Annotations, sketches, and feedback from all stakeholders

This eliminates the slowest, most painful part of every incident: figuring out what actually happened.

A dev-first debugging workflow ensures that the very first time an engineer opens a ticket, they already have the full picture. No Slack threads, no Zoom calls to “walk through what you saw,” no repeated requests for “more info,” no guesswork.

In 2025’s increasingly complex distributed environments, designing your debugging workflows around complete, structured, immediately available context is one of the highest-impact decisions you can make.

End-user support has always been messy. Manual steps, tool-switching, and scattered communication turn what should be a simple fix into a marathon of frustration.

Tickets feel like scavenger hunts: everyone’s searching for details, logs, screenshots, or that missing repro step.

Developers are left waiting on context that never arrives.

Support teams spend hours chasing updates across email threads and Slack channels.

And when context lives across ten tools, nobody gets the full story.

The result? High user satisfaction scores on paper and burned-out support and engineering teams behind them.

The usual support workflow

We’ve spoken with many of our users and they usually describe a support workflow that takes a multi-person, multi-email, multi-tool journey throughout their organization.

Here’s what “good” support often looks like in practice:

1. User reports an issue. A user reports an issue. Some companies have one ticketing system, others accept chat, email, bug forms, even social DMs. The same problem can arrive through multiple channels, which already splits the context.
2. End-user <> Support back-and-forth. The first ticket rarely contains everything a Support Engineer or Developer needs to fully understand the problem. You might get a symptom, a screenshot, or “it’s slow”. Support starts a back-and-forth to collect the missing pieces: steps to reproduce, browser and device, account, exact time, error messages. This can take hours or days as people reply in different time zones or forget details.
3. Handoff to engineering. With partial context gathered, Support passes the ticket along. Engineering reads the summary, opens the attachments, and tries to map the user’s description to how the system actually works. In many instances, reproduction attempts fall short: something is still missing, so developers need to ask Support for more info, or they go hunting for more details on their own.
4. Side quests multiply. Engineers search logs, traces, dashboards, and metrics. They check feature flags, versions, deployments, and documentation. They ask teammates if anyone touched that part of the system. Context is scattered across tools and people, which slows everything down.
5. Ticket escalations. While Engineering investigates, the customer grows impatient and escalates to the Account Executive or to leadership. Inside the company, the ticket rises to Senior Engineers and other teams. Meetings are scheduled to “sync on status,” which consumes time without adding new facts.
6. Stakeholder pile-on. Product, CS, QA, UX, and Sales all weigh in, each bringing partial data or new questions. Information fragments across email, Slack, comments, and docs. Keeping track of what is known becomes a task of its own.

Sometimes this results in user churn. Many times, however, the story appears to end well!

The customer finally gets the solution to their problem, leaves a nice review, maybe even a five-star CSAT (customer satisfaction) rating. On paper, it’s a success: the ticket is closed, the metrics look good, and everyone moves on.

But underneath, there’s a quiet cost. The team lost hours chasing context instead of solving problems. Engineers spent more time coordinating than coding. Support burned emotional energy just keeping the process afloat. And none of that shows up on your dashboards.

Is this type of “great support” sustainable?

What happens when your user base doubles, or when the engineering roadmap shifts and the same few people can’t jump on every urgent ticket? How do you maintain speed and quality without burning through your team’s time — and energy — every time an issue hits production?

A high CSAT score is easy to celebrate. But if it comes at the expense of your team’s focus, efficiency, and well-being, it’s not a sign of healthy support.

The solution

Multiplayer transforms the chaos of debugging and support workflow. We do this through full stack session recordings: complete, correlated replays that capture everything from the frontend to the backend.

That includes:

• User actions, on-screen behavior, clicks, and comments
• Frontend data: DOM events, network requests, browser metadata, HTML source code
• Backend traces with zero sampling, logs, request/response content, and headers
• CS, developer, and QA annotations, comments, and sketches

Instead of scattered tooling and guesswork, Multiplayer gives you one replay that tells the whole story: what happened, why it happened, and how to fix it.

Support engineers get clarity instead of chaos

Instead of chasing screenshots and guessing what really happened, support engineers open a ticket and see the full story: user actions, backend behavior, and all the technical details automatically captured.

No scavenger hunts, no Slack threads, no “please send more info.” Just instant visibility and a single source of truth everyone can work from.

They get:

• Automatic issue capture the moment something goes wrong
• A clear replay of user actions, clicks, and feedback
• A single shareable link for cross-team collaboration, complete with on-screen sketches, notes, and context

Developers get everything they wish every ticket included

By the time an issue reaches the Engineers, it already includes everything they need to reproduce and fix it. Multiplayer captures frontend and backend data, correlates it by session, and makes it available directly inside their IDE or AI tools.

No more grepping through logs or asking for repro steps. Just open the session, see what happened, and fix it.

They get:

• High-fidelity repro steps with full visibility into cause and effect
• Complete, unsampled full-stack data that’s already AI-ready
• Support for any language, environment, or architecture

Users get faster fixes and smoother experiences

From the user’s perspective, the magic is simple: they report an issue once, and it gets resolved quickly and accurately.

No endless email loops. No repeated questions. Just responsive, reliable support that feels effortless.

They get:

• Easy issue reporting through browser extension or in-app widget
• Fast, accurate resolutions even for rare, intermittent, or hard-to-reproduce bugs
• A better in-app experience, because every fix is grounded in real user data

Why it matters

When Support and Engineering are on the same page, everything moves faster. Users feel heard, Support teams stop chasing screenshots, and Developers can finally focus on building instead of firefighting.

Multiplayer was built for that kind of alignment: turning fragmented communication into shared understanding. We:

• Eliminate incomplete bug reports and endless back-and-forth
• Give every team the same full-stack context from the start
• Speed up escalations and shorten resolution time
• Surface root causes in minutes instead of hours (days?)
• Improve overall product quality with every fix

With Multiplayer, the session itself becomes the common language between end-users, Support, and Engineering.

No lost context. No burnout. Just clear visibility, faster fixes, and teams that can finally breathe again.

A full stack session recording captures the entire path of system behavior (from the frontend screen to the backend services) automatically correlated, enriched, and AI-ready.

In a single replay, you see:

• The screens and actions a user took
• The backend traces and logs triggered by those actions
• The request/response content and headers exchanged between all your components
• Metadata like device, environment, browser, etc.
• User feedback, plus annotations, sketches, and comments from the engineering team

Instead of stitching together screenshots, console logs, APM traces, and bug tickets, a full stack session recording shows you the whole story, end to end.

Traditional session replay tools

Most tools that promise “visibility” into your system fall into one of three buckets:

• Frontend session recorders (e.g. FullStory, LogRocket, Jam): Great at showing what the user saw and clicked, but they stop at the browser. Some bolt on backend visibility via integrations, which means extra cost, more tools to manage, and sampled data.
• Error monitoring tools (e.g. Sentry): Useful for flagging what broke, but it's not purpose-built for collaborative debugging workflows. When you need to resolve a specific technical issue, you're left sifting through sampled session replays, manually correlating disconnected context from separate tools, and coordinating slow handoffs between support, frontend, and backend teams.
• APM/observability platforms (e.g. Datadog, New Relic): Perfect for monitoring system health and long-term trends, but not for surgical, step-by-step debugging through a session replay.

How is Multiplayer different

Multiplayer is different. It gives developers the entire story in one session, so you don’t waste hours context-switching between tools, grepping through logs, or chasing repro steps.

✔️ Compatible with any existing ticketing help/desk system (e.g. Zendesk, Intercom, Jira)

✔️ Multiple options to record, install, and integrate session replays. Multiplayer adapts to your support workflow.

✔️ Developer-friendly and AI-native. Compatible with any observability platform, language, environment, architecture, and AI tool. You can also host in the cloud or self-host.

Everything you need, for any support scenario, out of the box

Multiplayer adapts to every support workflow. No extra tools, no manual workarounds, no rigid setup. Whether you’re handling a question about “unexpected behavior” or a complex cross-service incident, Multiplayer gives you the full context to resolve it.


What makes full stack session recordings powerful?

Where traditional replays stop at the UI, full stack session recordings go deeper, capturing the entire stack, automatically.

Multiplayer makes that power practical with:

• Full stack data by default: From user actions and feedback to backend traces and logs, including details most tools miss (like request/response content and headers from middleware and internal service calls).
• Flexible recording modes: on-demand, continuous, or conditional
• Multiple install options: browser extension, in-app widget, or SDK / CLI apps
• Rich collaboration features: view, share, and annotate every aspect and data point of a session recording or collaborate in notebooks (interactive sandbox environments) to auto-generate runnable test scripts, test complex API integrations, collaborate on feature requirements or visualize data sets. 
• AI-native design: feed your copilots and AI IDEs the complete system context they need.

With Multiplayer, a single session replay isn’t just a playback of what happened: it’s a complete, actionable view of your system that accelerates debugging, validates fixes, and fuels development.

Traditional "always-on" recording tools and APM platforms take the same brute-force approach: capture everything. Every session, every log, every metric, whether you need it or not. That flood of data creates its own problems: high storage costs, constant filtering and sampling, and hours wasted sifting for the signal inside the noise.

Multiplayer was built differently. We capture only what matters, and we do it in a way that stays lightweight and unobtrusive for users. When you need the full picture for a specific technical issue or complex, full stack bug, you have everything, correlated in one timeline.

Multiplayer setup 101

Multiplayer is designed to adapt to every support and debugging workflow, which is why we support:

• Three install options (in-app widget, browser extension, SDK/CLI apps)
• Three recording modes (on-demand, continuous, conditional)
• Multiple options on how to send telemetry data (and how much) to Multiplayer and how to deploy (self-hosted or cloud)

It's a "choose-your-own-adventure" type of approach so that teams can mix and match the install options, recording modes and backend configuration that best fits their application needs.

How Multiplayer stays lean

Modern teams are rightly sensitive to anything that could slow users down. Multiplayer is designed to capture useful context without adding noticeable latency or chewing through bandwidth/CPU. Here’s how we stay lean:

• Opt-in by default → If you’re not recording, there’s zero runtime overhead. Browser extension off? In-app widget not initialized? No impact.
• Event-based, not video-based → We capture structured events (DOM mutations, clicks, network metadata), not pixel streams. The result: smaller payloads, faster uploads, less CPU.
• Session-first, not “capture everything” → Multiplayer correlates full-stack data around the sessions you care about, instead of hoovering telemetry from your entire estate.
• Asynchronous, batched I/O → Uploads happen in the background, off the critical path. No blocking calls that slow users down.
• Backend-agnostic via OpenTelemetry → You control what’s instrumented and how much you emit, just like structured logging.

Recording modes: precision vs coverage

Most tools force a tradeoff: either record every session (expensive and noisy) or rely on on-demand captures (easy to miss unexpected issues).

Multiplayer gives you three recording modes that can be combined depending on your workflow:

• On-Demand: Nothing runs until you explicitly start recording via extension, widget, or SDK. Perfect when you want zero background footprint.
• Continuous: A lightweight rolling buffer (a few minutes of events) that auto-saves on errors/exceptions or when you choose to save. You catch elusive bugs without recording everything.
• Conditional: This is the most similar to traditional "always-on" session capture, with the difference that you pre-select specific conditions that will trigger the recordings. In short you're recording all sessions only for a specific cohort of users.

This versatile approach to choosing and combining multiple recording modes, gives you coverage without drowning in noise or adding unnecessary performance overhead.

Installation options: full control

Different teams have different needs. Multiplayer supports different install paths so you can control overhead and scope:

• Chrome browser extension
• In-app widget (JavaScript client library for web applications and React Native client library for mobile apps)
• SDK / CLI apps

We also offer self-hosted deployments (contact our team for more information).

Why our approach matters

Multiplayer gives you the control to record what you need, when you need it, without drowning in data or slowing down your users.

Whether you’re debugging, testing, supporting customers, or feeding AI copilots accurate context, you get the same promise: all the context, none of the noise.

Traditional session replay tools give you a window into what the user saw.

A few let you blur sensitive data or leave a quick sketch. Some rely on third-party integrations to manage annotations. Most just let you add comments to the overall recording.

What they don’t give you is a way to connect annotations to the actual system data: the API calls, traces, and logs that explain what really happened. And they certainly don’t make those annotations AI-ready, so you can feed them straight into your IDE or coding assistant.

That’s where Multiplayer annotations come in.

Practical use cases

Notes in Multiplayer transform raw session recordings into executable development plans. Whether you're debugging a technical issue, clarifying requirements, planning a refactor, or designing a new feature, notes capture your thinking directly on the timeline, attached to the exact moments, interactions, and backend events that matter.

Instead of writing requirements in a vacuum or describing bugs in abstract terms, you're annotating actual behavior with full-stack context automatically included.

(1) From Replay to Plan

This is how a traditional workflow might look like:

• Watch a session recording of the user actions (only frontend data)
• Switch to a separate tool (Jira, Linear, Notion)
• Try to describe what you saw in text
• Lose technical context in translation
• Respond to all the clarifying questions
• Repeat the cycle

With Multiplayer annotations:

• Watch the full stack session recording
• Sketch directly on problem areas as you see them
• Add timestamp notes explaining what should happen instead
• Annotate the specific API call or trace that needs modification
• Share the annotated recording with your team

The result is precise, contextualized instructions that include:

• Visual markup showing exactly which UI elements need changes
• Timestamp notes explaining the intended behavior at each step
• References to the actual API calls, database queries, and service traces involved
• On-screen text specifying new copy, error messages, or validation rules
• Sketched mockups showing proposed layouts or flows

Engineers receive a complete specification with runtime context.

(2) Cross-Role Collaboration

Annotations create a shared visual language that works across teams and disciplines:

Support → Engineering handoffs: Support annotates a customer's session with red circles around the confusing UI, timestamp notes explaining what the customer tried to do, and highlights on the error response that needs better messaging. Engineering sees the bug with full reproduction context in under a minute.

Product → Engineering workflows: PM annotates a user session showing where people drop off, adds sketches proposing a new flow, and attaches notes with acceptance criteria. Engineer reviews the annotated session and knows exactly what to build, with examples of the current behavior and references to the code paths involved.

QA → Development feedback loops: QA records a test run, annotates edge cases with highlights, adds notebooks with each test scenario, and circles areas where behavior differs from specs. Developers receive visual test documentation tied to actual execution traces.

Engineering → Vendor communications: When working with third-party APIs or external teams, engineers can record integration behavior, annotate failing requests with technical details, sketch expected responses, and share the annotated session. Vendors see exactly what's happening in your system without needing access to your codebase.

AI-Ready Context

Use the Multiplayer MCP server to pull your full stack session recording screenshots and notes into your AI coding tools.

Because annotations carry metadata, they’re machine-readable. They’re not just helpful for humans, they’re structured context your AI tools can consume directly.

This means your copilot doesn’t just “see” a session: it understands the requirements, context, and team intent tied to that session. From there, it can generate accurate fixes, tests, or even implement new features with minimal prompting.

Traditional AI prompting:

"Add validation to the signup form"

AI generates generic validation without knowing your form structure, existing patterns, or backend constraints.

AI prompting with annotated sessions:

Share an annotated Multiplayer recording showing:
- The signup form with red circles around fields needing validation
- Timestamp note: "Email validation should reject addresses without proper domains"
- Highlighted API call showing the current /signup endpoint contract
- Text annotation specifying error message copy
- Trace showing the validation happens client-side only (needs backend validation too)

AI now has:

• Visual context of your actual UI
• Specifications for the exact behavior you want
• Technical context of existing API contracts
• Requirements for both frontend and backend changes
• Examples of current behavior vs. desired behavior

AI-powered IDEs and copilots have made it easier to scaffold code and suggest fixes, but when it comes to debugging real systems they often fall short.

The problem isn’t with the models themselves: it’s with the data they’re given. Without full context, AI assistants hallucinate plausible-sounding (but useless) fixes. Developers are forced to bounce between logs, traces, dashboards, and bug reports to piece together the real story, wasting hours on context switching. Even then, it usually takes multiple rounds of prompting and refinement before the AI produces something actionable.

Existing MCP servers address part of the problem. But only part. Some surface APM data like backend traces and metrics, others expose frontend replays. Useful, but again, incomplete.

What they don’t provide is the full picture: frontend screens, backend data, user steps, and team annotations correlated together. Exactly the kind of context a developer would need before coding a fix.

Multiplayer MCP server overview

The Multiplayer MCP Server makes full stack session recordings available to MCP-compatible AI tools like Cursor, Claude Code, Copilot, or Windsurf.

Instead of giving your IDE a sliver of the picture (i.e. just observability data from an APM tool, or just a frontend replay) you can now feed it the entire session context:

• Frontend screens and data (console logs, network requests, and device details, etc.)
• User actions and feedback
• Backend traces, logs, requests/response content and headers
• Annotations, comments and sketches from the engineers, directly on the recording

That means no missing data, no guesswork. Your copilots stop hallucinating fixes for issues that don’t exist and start producing accurate code, tests, and features with minimal prompting.

Imagine telling your IDE: “Implement this new feature based on the requirements in this recording,” and actually getting code that compiles and runs.

How it works

Multiplayer is designed to adapt to every support and debugging workflow, which is why we support multiple install options, recording modes and multiple options on how to send telemetry data (and how much) to Multiplayer.

It's a "choose-your-own-adventure" type of approach so that teams can mix and match the configuration that best fits their application needs. Once you've fully configured Multiplayer, you can:

1. Capture a full stack session recording: Capture the entire stack (frontend screens, backend traces, logs, metrics, full request/response content and headers) all correlated, enriched, and AI-ready in a single timeline.
2. [optional] Annotate: Add sketches, notes, and requirements directly to recordings. Highlight interactions, API calls, or traces and turn them into actionable dev plans or AI prompts.
3. Install: The MCP server makes all that rich session data available to copilots and IDEs.
4. Act: Ask “Fix the bug from this session,” or “Move this button based on the sketch in this recording” and get accurate results without hunting data.

Choose your preferred tool and follow the setup guide:

• Cursor
• Visual Studio Code
• Claude Code
• Copilot
• Windsurf
• Zed
• Manual

Multiplayer MCP server in action

Debugging

Priya C. (Developer, Insurance Company) uses Multiplayer MCP to debug her distributed system issues by providing Cursor with a full-stack session recording. Instead of juggling logs, traces, and Slack threads, she sends the session recording context directly into her AI IDE to diagnose and resolve the bug faster.

An example prompt that she uses is:

Review this Multiplayer session recording < Session Link Placeholder >. Analyze the user actions, backend traces, and logs to identify the root cause of the failure. Provide a step-by-step debugging plan and suggest code changes needed to resolve the issue.

Feature development

Luis G. (Principal Engineer, FinTech Company) uses Multiplayer MCP to transform full-stack session recordings into feature development plans. By annotating directly on session replays (highlighting API calls, backend traces, or UI elements) he provides his AI IDE with precise, context-rich requirements for implementing new features without ambiguity.

An example prompt that he uses is:

Review this Multiplayer session recording and notes for < Session Link Placeholder >. Use the highlighted API calls and UI sketches to generate a development plan, including new routes, backend changes, and frontend updates. Provide proposed code snippets for each step.

System exploration and understanding

John V. (Product Manager, Commercial Bank) uses Multiplayer MCP to analyze full-stack session recordings and uncover how their complex system behaves under the hood. By feeding end-to-end data into his AI assistant, he can explore how features interact across services and anticipate the downstream impact of proposed changes before they’re implemented.

An example prompt that they use is:

Review this Multiplayer session recording < Session Link Placeholder >. Analyze the top-level and error traces to explain:- Which core services and APIs were involved in this workflow.- How these components might affect downstream components or user experience.- Provide a summary that highlights potential bottlenecks or areas for improvement.

Your AI IDE is only as smart as the data you give it

At the end of the day, your AI IDE is only as smart as the data you feed it.

Other MCP servers can help, but with partial context you still get partial results. Multiplayer MCP delivers the whole stack: frontend screens, backend traces, logs, request/response content, headers, and team annotations, all correlated in a single session.

Which means faster fixes, fewer regressions, and less back-and-forth between humans and machines. That’s how you turn copilots and coding agents into genuinely useful partners in day-to-day engineering.

Most session recording tools force you into a tradeoff:

(1) On-Demand recording

Tools: Screen capture, Loom, Jam
The promise: Record only what matters, when you need it.
The reality: You only capture what you remembered to start recording.

The problem? The most important moments are unexpected. A user encounters a critical bug at 3 PM, but you don't hear about it until the next day. By then, reproducing the exact steps and system behaviour is a manual, time-consuming process. You're left asking the user to "try to reproduce it" while remembering to start a screen recording, hoping lightning strikes twice.

Engineers waste hours attempting to reproduce issues based on vague descriptions. Support teams send lengthy back-and-forth emails trying to extract details. The actual evidence? Already lost.

OR (2) Always-on recording

Tools: Sentry, Fullstory, LogRocket , etc.
The promise: Capture everything so nothing gets missed.
The reality: You capture everything, including the 99.9% of sessions that don't matter.

This is what we usually think of when we hear "continuous" recording. I think a more accurate description would be "always-on" frontend recording (by default) that stops at the browser boundary, leaving you blind to the full-stack context that actually explains what went wrong.

Teams end up drowning in data, burning storage on noise, and wasting hours filtering to find the handful of sessions that matter. Worse, these tools only capture the part of the picture. When you finally find the relevant session, you still need to:

1. Open your APM tool to find the corresponding (sampled?) backend traces
2. Check your logs for related errors
3. Query your database to understand data state
4. Correlate timestamps manually across systems
5. Hope all the pieces line up

Multiplayer takes a different approach

Instead of recording every second of every session forever, we give you options: three recording modes to fit your specific workflow or immediate needs.

No matter the type of technical issue (vague user report, intermittent, hard-to-reproduce, across your stack, etc.) you’ll have the visibility you need to debug, validate, and build with confidence.

On-demand recording

Capture full stack session recordings on demand: manually start and stop a session replay with a browser extension, in-app widget, or SDK.

End-users, support teams and engineers can instantly record and share issues, understand user and system behavior, and collaborate on how to solve them.

Continuous recording

This is Multiplayer's take on the traditional "continuous" recording mode: a middle ground between on-demand and "always-on".

You manually start the recording, and we keep a lightweight rolling buffer while you work, adding no latency to your process. If an issue arises, you can instantly save the last snapshot, no need to start the recording and try to reproduce the issue.

We also auto-save sessions when frontend or backend exceptions and errors occur, so you’ll always have the critical context when something breaks.

The result: less wasted time searching, lower storage overhead, and higher confidence that the sessions you need are always there.

Conditional recording

This is the replay mode most similar how traditional session replay tool record your user session, but with a more control.

You can record session replays in the background for a specific cohort of users, based on pre-defined conditions.

This mode still allows you to silently capture user sessions without any manual steps, allowing you to detect issues even when users don't notice or don't report them. However, it's more lightweight and targeted than the traditional "always-on" recording.

It's not "all or nothing". Flexibility in recording modes matters.

With Multiplayer, you’re not locked into a single recording strategy. On-demand, continuous, and conditional modes work together, so your team can choose the right balance of precision, automation, and coverage.

End-to-end visibility is the baseline. Multiplayer captures the full stack out of the box (frontend interactions, backend traces, logs, request/response content, and headers) so you get the right data.

And with the option to choose (or combine) recording modes, you always have the right data at the right time, without drowning in noise or losing the context you need to fix, validate, and move forward.

Backend tracing is the backbone of understanding how modern distributed systems behave. Each request generates a chain of spans as it travels through your services and components: what happened, how long it took, and whether it failed. Stitch those spans together, and you get a trace: the full story of a request from start to finish.

That’s the theory. In practice, most tools only give you part of the story.

The problem with sampling in APM tools

APM platforms ingest massive volumes of telemetry, and to keep costs under control they sample aggressively: only a fraction of traces are kept. That works fine for monitoring overall trends and system health, but it breaks down when you need to debug a specific issue or bug.

You can easily miss the trace that actually matters, or waste hours stitching it together from fragments.

I talked about this in our recent webinar, How left-shifted observability speeds up debugging. In short, teams often fall into a vicious cycle:

• You spend a large share of your budget collecting telemetry, but most of it sits unused.
• To cut costs, you reduce tool sprawl or turn to pre-aggregation and trace sampling.
• Inevitably, you lose the detail that makes debugging possible or you burn engineering hours trying to balance “enough detail” against “not going bankrupt.”

Why Session replay tools don't fix it either

If APM tools sample away the traces you need, session replay might seems like the answer with their targeted approach. However, most stop at the frontend. They show you what users clicked and where they got stuck, but not why your application behaved that way.

The tools that claim "full-stack visibility" typically work in one of two broken ways: they either piggyback on your existing APM (inheriting its aggressive sampling or lack of deeper information such as request/response payloads from internal service calls), or they require brittle manual instrumentation where you're responsible for capturing and correlating API calls, traces, and errors yourself.

Either way, you're still missing the technical context when debugging. You see the user encountered an error, but the API trace that explains why was sampled away or never captured at all.

How Multiplayer does it differently

When you start a session recording in Multiplayer, we capture every backend trace connected to that session, with zero sampling.

Here’s what happens under the hood:

• Multiplayer generates a unique trace context for the session (trace ID + span IDs). In OpenTelemetry terms, this is a TraceContext that travels with requests as they flow through your system.
• In OpenTelemetry, each trace has a traceFlags field, which includes a sampling bit (often called the “sampled” flag). Normally, your observability platform has a cardinality threshold based on which it decides whether to sample (keep) a trace or drop it. Multiplayer sets the sampled flag to true at the root span, so all spans in the trace are preserved. In short, for each session we keep everything.
• As the request travels across services and components, OpenTelemetry propagates the trace context via headers (traceparent, x-trace-id,x-span-id, etc.). Every service that participates in the session inherits the “sampled = true” flag, ensuring that no span gets dropped along the path.
• OpenTelemetry SDKs and collectors gather all spans, logs, and metrics. Review our backend configuration step for customization options.
• Multiplayer correlates that backend data with the frontend replay and user actions in one timeline.

You can even enrich sessions with request/response content and headers from deep within your system (i.e. middleware and and internal service calls), so your recordings carry the exact system-level detail you need.

Why zero sampling matters

With Multiplayer, you don’t just hope the trace you need was captured; you know it was. That means:

• Confidence you’ll have the data for any bug, no matter how rare or hard to reproduce.
• Precision in debugging: see exactly how a user action propagated across services.
• AI-ready context: feed your IDE or copilot the complete, correlated trace plus everything else from the recording: frontend screens, user actions, team sketches and notes.

You get the whole story, every time, without the overhead of “log everything” and without the blind spots of sampled traces. That’s what makes full stack session recordings more than just a replay.

Today might be one of the biggest Product Hunt launch days in recent weeks: Claude, DeepSeek, OpenAI, Lovable, Squarespace … a whole lineup of giants dropping new, amazing products.

My LinkedIn feed is a wall of “Thrilled to announce!” and “Show your support!” posts.

And let’s be real: Product Hunt isn’t what it used to be. There’s even a recent Hacker News thread breaking down how the game is rigged: agencies, paid boosts, and all the machinery behind the scenes. The odds of a smaller startup cracking the top 5 on pure user love? Close to zero.

So why launch Multiplayer on Product Hunt at all? And today, of all days?

A chance to tell our story

Because even if the leaderboard is stacked, someone who’s never heard of Multiplayer might stumble across us and share their thoughts. And that’s what matters most to us: your feedback.

We’d rather talk to developers than chase orange upvotes.

So much so that we’re asking you NOT to upvote us. If you want to help, leave a comment. Tell us what works, what doesn’t, and what you’d change.

Or, better yet, skip Product Hunt entirely. Try full stack session recordings yourself:

👉 Free sandbox: sandbox.multiplayer.app
👉 Free 1-month trial: go.multiplayer.app
👉 Or just send us feedback on any channel, roast included 😅

How is Multiplayer different

At Multiplayer we focus on one thing: full stack session recordings. Here’s what sets us apart:

• Full stack out of the box. Traditional replays stop at the UI. We go deeper, capturing frontend screens and backend traces, logs, metrics, request/response content, and headers. All auto-correlated, enriched, and AI-ready.
• Annotations everywhere. Add sketches, comments, and requirements not just on screens, but on user actions, traces, spans, and API calls. Every part of a session can contain developer context.
• Built for AI-native workflows. Each session is a self-contained, pre-correlated dataset that copilots and IDEs can consume directly. That means your AI tools get the right context across the stack to generate accurate fixes, tests, or features, without blowing your token budget.
• Backend agnostic, OTel-compatible. Multiplayer works with whatever observability stack you already use. No vendor lock-in, no need to switch between APM tools just to enrich your data.
• Versatile by design. Choose how you capture: browser extension, in-app widget, SDK, or mobile. Choose how you record: on-demand, continuous, or remote. Customize backend data capture to fit your system.

How you can support us

We launched today not to “win” Product Hunt. Developer tools should be judged on what they actually do. That’s why what we want is your perspective:

👉 Would you use full stack session recordings mainly for debugging, testing, or feature development?
👉 Have you tried session replays before, and if so, what worked (or didn’t) for you?
👉 What’s the one feature you wish we supported?

Multiplayer isn’t another replay tool or another observability dashboard.

It’s the connective tissue that lets developers see a system end-to-end, add the context that usually gets lost in tickets or Slack threads, and feed all of it directly into AI coding tools or share with their teammates.

Where others stop at recording or monitoring, we help you capture, understand, and act, all from a single session. That’s why we’re betting big on full stack session recordings: because visibility is only valuable if it helps you and your team move faster with confidence.

1 Oct 2025 update.

It seems that the way to play the Product Hunt game... is not to play it?
We ended up #8 🤷

Distributed debugging isn’t just traditional debugging at scale, it’s an entirely different challenge. It means diagnosing and fixing issues that span multiple services, layers, and sometimes even teams, across complex and often legacy architectures.

These aren’t just bugs. They’re emergent behaviors, cascading failures, and tricky edge cases that don’t show up until just the right (or wrong) combination of conditions is met.

Here’s what makes distributed systems especially hard to debug:

• Unpredictable failures are inevitable. In a system running on a single machine, hardware-level issues like memory corruption are rare. But at the scale of tens of thousands of machines, something is always broken. You can’t eliminate failures: you have to design for them, detect them quickly, and recover quickly.
• Failures have multiple root causes. In complex systems, incidents are rarely caused by a single issue. More often, they’re the result of several factors aligning: an overloaded service, a misconfigured retry, a recent deploy. This makes incident analysis far more about understanding the context than isolating a single line of faulty code.
• Non-deterministic behavior is common. Distributed systems introduce uncertainty: network delays, retries, clock skew, and asynchronous workflows all create variability. The same inputs won’t always produce the same results, which makes consistent reproduction one of the hardest parts of debugging.
• Concurrency and inter-process interactions create hidden chaos. Multiple services run in parallel, often communicating asynchronously. Debugging across these boundaries requires stitching together logs, traces, and system state.
• No one has the full picture. Modern systems are too large and too fast-moving for any single engineer to have a complete mental model of the entire system. As systems scale, knowledge fragments, and institutional knowledge gets lost. Debugging becomes not just a technical task, but a coordination challenge across people, tools, and documentation.

Four key practices to reduce Mean Time to Resolution (MTTR)

Mean Time to Resolution (MTTR) measures how quickly your team can detect, diagnose, and resolve issues, minimizing downtime and user impact. It's one of the most critical metrics for engineering teams, yet in modern distributed systems, fast resolution remains frustratingly difficult.

The problem isn't lack of effort. It's lack of context. Bugs surface unpredictably, evidence is scattered across multiple tools, and by the time someone reports an issue, the technical context has already disappeared or been sampled away.

To improve MTTR, teams need practices and tooling that reduce friction at every stage of debugging. Here are four critical ones:

1. Capture complete technical context automatically

Most bugs span the entire stack: a confusing UI stems from a malformed API response, which traces back to a slow database query, which connects to a misconfigured service. Yet traditional debugging methods force you to hunt across multiple platforms: session replay for frontend, APM for traces, logs for errors, database tools for queries.

Multiplayer automatically correlates everything. When something goes wrong, you get the complete technical story: the user's interactions, the API calls they triggered, the backend traces that processed those requests, and the database queries that executed. All in one timeline, with zero manual correlation.

No jumping between tools. No guessing at timestamps. No missing context because something was sampled away. The evidence exists, automatically captured and connected, the moment an issue occurs.

2. Start from the technical event, not the symptoms

Traditional debugging workflows start with symptoms: "users report the checkout is broken." Then comes the archaeology: searching logs, filtering APM traces, trying to find relevant sessions, hoping you can piece together what happened.

Multiplayer inverts this. It captures sessions triggered by technical events across your stack: API failures, performance degradation, exceptions, critical business flows. When something goes wrong, the evidence is already there, complete and contextualized.

Instead of starting with vague user reports and working backward, you start with the technical moment something broke: the exact request, the stack trace, the database state, the user's actions, all captured together. Your team spends time fixing issues, not hunting for clues.

3. Turn debugging sessions into executable test cases

Reproducing bugs in distributed systems is notoriously difficult. By the time someone reports an issue, the database state has changed, authentication tokens have expired, or timing-dependent race conditions are impossible to recreate manually.

Multiplayer lets you generate executable Notebooks directly from captured sessions. The system auto-captures all relevant API calls, authentication headers, request payloads, response data, and execution logic, then transforms it into a runnable test script that reproduces the exact conditions where the bug occurred.

Developers get immediately reproducible test cases instead of vague reproduction steps. QA can verify fixes against real failure scenarios. The same session that revealed the bug becomes the test that prevents regression.

4. Make debugging insights shareable across teams

Bugs don't exist in isolation: they require collaboration between frontend engineers, backend developers, DevOps, support, and sometimes external vendors. Yet traditional tools trap context in formats that don't translate: log files backend engineers understand might not mean much to support.

Multiplayer makes technical context universally understandable. Record a full stack session replay and then annotate it with your comments.

Draw on the UI where something broke, add timestamp notes explaining what should happen, highlight the failing API trace, sketch proposed fixes. Support can document customer issues with full technical detail. Engineers can leave visual feedback on implementations. Teams can communicate across disciplines using the actual behavior of the system.

The same annotated session that helps support explain a customer issue becomes the specification engineers use to fix it—and the test case QA uses to verify it.

How to use the Multiplayer

We’ve talked about the best practices to reduce MTTR in distributed systems, now here’s how to put them into action, faster.

Multiplayer is designed to adapt to every support and debugging workflow, and today we're releasing our browser extension.

Now we support:

• Three install options (in-app widget, browser extension, SDK/CLI apps)
• Three recording modes (on-demand, continuous, conditional)
• Multiple options on how to send telemetry data (and how much) to Multiplayer and how to deploy (self-hosted or cloud)

It's a "choose-your-own-adventure" type of approach so that teams can mix and match the install options, recording modes and backend configuration that best fits their application needs.

With one click, Multiplayer now turns full stack session recordings into test scripts that capture:

• Every API call, payload, and header
• The exact sequence that triggered the failure
• A live, editable notebook your team can run, test, and verify

Distributed debugging stages

"Debugging" is often used as a broad umbrella term. It covers everything from realizing something's broken to confirming it's fixed. But when engineers talk about debugging as a process, they often break it into stages. Especially when thinking about complex, distributed systems.

Here’s how engineers typically break it down:

1. Detection - “Something’s wrong.”

You spot an alert, error message, customer support ticket, unexpected behavior, or test failure. You know there’s a problem, but not much more.

2. Root Cause Analysis - “Why is this happening?”

This is often the hardest part of debugging, because you need to find what’s actually broken (the “what”, “when”, “why” and ”how”), not just the symptom.

In distributed systems, it gets tricky fast: logs, traces, metrics, recent deployments, and tribal knowledge must all be pieced together. Issues can span services, teams, or even regions, and the point of failure is rarely where the symptoms show up.

3. Reproduction - “Can I trigger this reliably?”

Before you can fix a bug, you need to understand it. And that often means reproducing it.

But distributed systems introduce complexity: timing issues, race conditions, and load-sensitive behaviors can make bugs intermittent and hard to isolate. Reproduction may require mocks, test harnesses, or simulated environments that reflect the exact state of the system at the time of failure.

4. Resolution - “Let’s fix it.”

Finding a fix is often a trial and error approach and might require coordination across multiple service owners. Fixes can span application logic, infrastructure, deployment configs, or third-party systems.

Given that issues in distributed systems are often caused by multiple root causes coming together as a perfect, unpredictable storm, developers need to have full visibility of how any change will affect the overall systems and all downstream dependencies. One change in a service can affect dozens of others.

5. Verification - “Did we fix it?”

Once fixed, you need to make sure it stays fixed.

This often means replaying the scenario, running regression tests, and monitoring closely to ensure nothing else broke along the way. In distributed systems it’s a continuous process of validation under real-world conditions.

Common downsides in traditional bug reproduction and resolution

Uncovering the root cause of an issue in distributed systems can be challenging. But even after detection, developers often face major roadblocks during reproduction and resolution:

• Test bias and incomplete coverage: Engineers naturally write tests based on assumptions or imagined failure paths. This often misses real-world bugs, especially those triggered by edge cases or unpredictable system behavior.
• High maintenance cost: As products evolve, test scripts quickly become outdated or time-consuming to write manually. Keeping them current consumes time that could be better spent on development or testing itself.
• Hard-to-reproduce bugs: Some failures rely on specific timing, state, or data conditions that are hard to replicate outside of production.
• Poor collaboration and visibility: Reproduction steps are often buried in Slack threads, untracked documents, or someone’s local setup; slowing down teamwork and increasing risk.
• Retroactive test creation is hard: After fixing a bug creating a useful test from memory is time-consuming and often misses critical context.
• Limited protection against regressions: Without accurate, reproducible tests tied to past bugs, it’s easy to accidentally reintroduce issues during future changes.

The result? With traditional approaches, engineering teams are forced to weigh the time and effort to build a test script against the time it takes to manually verify the bug, factoring in not just engineering hours, but lost momentum and opportunity cost.

Auto-generated, runnable test scripts

Multiplayer’s full stack session recordings allow developers to quickly and accurately identify the root cause(s). They capture everything you need to understand a bug, from frontend screens, backend traces, logs, full request/response content and headers. All in a single, sharable and annotatable timeline.

But that’s only half the equation: now they have to reproduce it and resolve it.

That’s why we’re introducing the ability to generate a notebook directly from a deep session replay of your bug. This auto-generates a runnable test script (complete with real API calls, payloads, and code logic) that mirrors the failure path.

This bridges the gap between observation and action.

With this release, developers can:

• Reproduce issues effortlessly: Notebooks capture the exact sequence of API calls, headers, edge-case logic, and system behavior that led to the bug, making it easy to simulate and understand the issue.
• Collaborate with full context: Share a complete, interactive snapshot of the bug. No more guessing, re-explaining, or syncing across tools. Everyone immediately understands the problem and can test it themselves.
• Verify fixes immediately: Modify API or code blocks to test potential fixes. Re-run the Notebook to confirm your patch resolves the bug before shipping. It acts like a unit or integration test, but targeted to the exact failure path.
• Document real behavior: Use Notebooks to record how systems actually behave in production, including edge cases and unexpected flows. Great for onboarding, audits, or future reference.
• Prevent regressions: Re-run the Notebook after code changes to ensure the bug stays fixed. It acts like a custom, high-fidelity regression test, built straight from the incident.

Sandbox notebook examples

The best way to understand how notebooks work, is to see practical examples. So here are some notebooks you can explore in our free sandbox:

• example-0-testing-notebook-blocks: Overview of all the text / API / code / visual blocks supported in notebooks
• example-1-authentication-using-reqres: An example notebook using reqres API
• example-2-internal-api-wiremock: An example notebook of an internal API mocked using WireMock
• example-3-shipping-easypost-api: An example notebook using EasyPost API
• example-4-time-travel-testing: An example notebook of a testing spec document for the Multiplayer’s "Time travel" demo app, which feeds data into this sandbox project
• example-5-time-travel-debugging: An example of a test script automatically generated from a full stack session recording of the Multiplayer’s "Time travel" demo app

By checking the last example, you'll see how auto-generated test scripts help eliminate:

• Guesswork in reproducing bugs
• Time spent building brittle test environments
• Gaps in communication and handoffs
• The risk of forgetting what actually happened

They don’t just help you fix the bug, they leave you with a runnable, verifiable notebook that prevents it from coming back.