Wrote the onboarding doc nobody asked me to write and it changed how the team treats me

I joined in January and spent three weeks in the classic new-hire fog. Nine repos and no idea which four mattered, no idea who to ask about what, and a local setup that needed a specific Node version documented precisely nowhere.

So I kept notes as I suffered through it. Purely selfish, I just didn't want to re-learn any of it.

When the next person joined in May I spent an afternoon cleaning it up and dropped it in the repo. She was productive in about four days.

What I didn't expect: my lead brought it up in my probation review, unprompted, as the main example. I've been treated as noticeably more senior since, and the actual code I write has not changed at all.

If you're new somewhere right now, keep the notes. The window where you can still see what's confusing closes fast, and you can't get it back once it does.