Reading Code You Did Not Write

The instinct is to read a codebase top to bottom like a book. Do not. Start from the edges — the entry points, the routes, the CLI commands — and trace one real request all the way through.

Rename things in your head as you go. If a function is misnamed, that is a signal about where the abstractions have drifted from reality.

Write down your assumptions as you form them. Half of them will be wrong, and finding out which half is the whole job.