On reading the source code

The most reliable way to get better at our trade isn't tutorials. It isn't a course. It isn't even side projects. It's reading the source code of the libraries you use every day — carefully, slowly, with the docs closed.

Start small. Pick a function you use weekly — `useState`, `Array.prototype.flat`, Tailwind's `merge` — and read the implementation. Don't skim. Trace the types. Click through the call graph.

After a few months of this, two things change. First, your bug-fixing speed doubles, because you stop guessing at black-box behavior. Second, the boundary between 'library' and 'my code' dissolves.