Documentation Is Love Letters to Future You

🧠 Dev Motivation — June 28, 2026

Documentation Is Love Letters to Future You

It's a Tuesday. You inherited payment-webhook-processor-v2. No README. One comment: # don't touch this on a 312-line function. A module called legacy_utils isn't in requirements.txt but somehow the service runs because it was installed globally.

Three hours later you understand the comment. The function makes four HTTP calls in a specific order depending on global state. Retry logic only works because the third API returns 503 first — handled by falling through to a different endpoint. Reorder anything → everything implodes.

You fix it. And the first thing you write after your code is a README.md explaining what it does, why calls happen in that order, and what breaks if you change the retry logic.

"Code tells you how. Documentation tells you why. And 'why' is the only thing that survives a rewrite."

The mindset shift:
❌ "Documentation is what you do after the feature ships."
✅ "Documentation is part of the feature. If it's not documented, it's not done."

You don't need a 50-page manual. You need a README.md that answers: What does this do? Why does it exist? What breaks if I change X?

Future you will show up at this codebase tired, under deadline, and emotionally compromised. Be kind to that person. Write the note.