[Part 5] Developer onboarding: documentation common mistakes

When a new person joins your team, everything comes at them all at once: new projects, processes, tools, technologies, and codebase. In this blog post series we talk about the best strategies that can transform a potentially overwhelming transition into a seamless and productive journey.

(1) Improving your developer onboarding approach
(2) Developer onboarding: best practices
(3) Developer onboarding: smart habits
(4) Developer onboarding: documentation must-haves
(5) Developer onboarding: documentation common mistakes

A negative onboarding experience can make new hires twice as likely to look for other jobs in their first year. Not to mention that a poor onboarding process lengthens the already long ramp-up period, delaying when a new engineer will reach their optimal productivity.

Ultimately, companies that invest in the onboarding process and avoid the following mistakes ensure higher overall effectiveness, quicker product development, and a lower risk of turnover.

(1) Don't underestimate the impact of onboarding documentation

Documentation is a powerful tool that sets the tone for the overall success of onboarding. Lack of good documentation not only slows down the entire onboarding process and adds overhead to the team, it's also a red flag indicative of deeper problems within the engineering culture and work.

What "good documentation" looks like:

Good documentation is comprehensive, accessible, current, and actually useful. The best onboarding documentation:

• Is in sync with your actual system, which may seem obvious but it's very hard to achieve without auto-documenting tools (especially in distributed systems)
• Provides context and "why", not just procedures and "what"
• Is discoverable when someone needs it, with clear organization and search functionality
• Shows real examples from your actual codebase and user session replays, not generic tutorials
• Acknowledges what's broken or confusing

Poor documentation sends the message to new hires that "We don't value knowledge sharing or your success." Great documentation sends the opposite message: "We've thought about your experience and want to set you up for success."

(2) Don't reinvent the wheel, leverage the right tools

The documentation has to be accurate, updated, and colocated in a single place. It's almost more harmful to have documentation that is incomplete, contradictory, and scattered throughout an unknown number of different systems, than having no documentation at all.

However, this doesn't have to be a manual, burdensome, and time-consuming task for the development team. In fact, most teams have moved beyond static wikis and Word documents scattered across drives. Effective documentation strategies include:

Auto-generated documentation: Use tools that generate documentation from code annotations, API definitions, or system telemetry. Architecture diagrams that auto-update, API docs that stay in sync with your code, and session recordings that document actual system behavior all reduce manual documentation burden.

Single source of truth: Choose one platform as your primary documentation home. Having documentation in Slack threads, email chains, Google Docs, wikis, and README files makes it effectively undiscoverable.

Interactive documentation: Rather than just describing how something works, provide interactive examples, sandboxes, or recorded sessions that new engineers can explore hands-on.

The goal is to make documentation so easy to create and maintain that it actually stays current. If documenting something is painful, it won't get done.

(3) Don't treat documentation as "just for onboarding"

The value of the documentation you're preparing extends far beyond the initial onboarding process. Consider it as an ever-evolving playbook of your team's operations.

Knowledge preservation: You don't have to be concerned that valuable knowledge will walk out the door just because a developer does. When critical context lives only in people's heads, every departure creates knowledge gaps.

Reduced context switching: Team productivity is maximized when people have the information they need, exactly where and when they need it. In the midst of complex projects or when troubleshooting issues, having a centralized source of information eliminates confusion and accelerates collaboration. Engineers spend less time hunting for answers and more time building.

Code quality and maintainability: A better understanding of how the codebase fits together avoids the proliferation of dreaded spaghetti code. Even when your codebase contains lots of legacy code, it's well understood and it'll be easier to refactor when the time comes.

Asynchronous collaboration: In an era of distributed teams across offices and time zones, being able to find the information you need async means higher productivity: you don't have to wait for someone in another time zone to wake up and respond to your questions.

Compliance and security: For regulated industries, documentation is required. Having processes, security practices, and architectural decisions documented helps with audits and compliance reviews.

(4) Don't skip the debugging and observability documentation

One critical piece that many teams overlook is documenting their debugging and observability practices. New engineers need to know:

• What tools are available for investigating issues
• How to access logs, metrics, dashboards, and session recordings
• Common debugging workflows and where to start when something breaks
• Examples of past incident investigations they can learn from

Without this documentation, new engineers either bother senior teammates with basic questions or struggle in silence, afraid to ask. Neither outcome is good for the team or the individual.

Modern dev tools (including full stack session recordings that capture complete user interactions and system behavior) provide valuable context for understanding production issues. But these tools are only helpful if new engineers know they exist and how to use them.

(5) Don't forget to gather feedback and iterate

The best onboarding documentation is written by people who recently went through onboarding. Their fresh perspective reveals what's actually confusing versus what veteran team members assume is obvious.

Make feedback part of the process:

• Ask new hires to document their questions and stumbling blocks during their first month
• Schedule a "documentation retrospective" at the 30-day and 90-day marks
• Encourage new engineers to propose documentation improvements as they discover gaps
• Track which documentation gets used most (and least) to identify high-value areas for improvement
• Celebrate and recognize contributions to documentation—it's real work that benefits the entire team

Documentation that never changes is dead documentation. The engineering landscape evolves, your systems change, and your processes mature. Your documentation should reflect that evolution.

Final thoughts

By recognizing the lasting impact of onboarding documentation, companies can invest wisely in their efforts, nurturing a thriving engineering culture built on the solid foundation of knowledge and collaboration.

The teams that document well onboard faster, maintain better code, respond to incidents more effectively, and retain their talent longer.

Make documentation a priority. Your future self (and your new hires) will thank you.