Claude reads your CLAUDE.md file. Write it for Claude.

“What should I put in my CLAUDE.md” is the question I hear most from engineers trying to speed up their work.

The common mistake is treating it as documentation for product managers. “We’re explaining what the code does anyway, so we’ll use it as docs.” Wrong.

Give Claude directions for finding the right information.

Bad: “In the class Calculator I export the methods sum and subtract.”

Good: “To do math, look at the Calculator class.”