Documentation
Overview
Documentation captures decisions, usage, and operational context so the team does not need to rediscover it.
Why It Matters
Good docs prevent repeated questions, reduce tribal knowledge, and speed up onboarding.
Core Concepts
- Document the why, not just the what.
- Keep docs close to the code or workflow they describe.
- Update docs when behavior changes.
Mental Models
Treat docs as an interface: they should be easy to find, easy to scan, and hard to misunderstand.
Best Practices
- Write in short sections.
- Add examples and links.
- Prefer one source of truth.
Common Mistakes
- Writing long prose with no structure.
- Letting docs drift from reality.
- Duplicating the same instructions in multiple places.
Trade-offs
Documentation takes time up front but reduces repeated support later.
Decision Framework
- Is the information reused?
- Will future-you need this context?
- Should it live in a doc, checklist, or playbook?
Examples
- Add a short “how to test” section to a feature doc.
- Link the architecture decision instead of restating it.
Checklists
- Is the doc current?
- Is the purpose clear in the first screen?
- Are related docs linked?
Senior Engineer Notes
Senior engineers write docs that help people act, not just read. If a doc does not change behavior, it probably needs a stronger purpose.