CEO of Y Combinator shared his
CLAUDE.md prompt for Claude Code
It helps him ship 4,000 line features with full tests in about an hour:
This prompt pushes Claude to:
Decide if the plan is overbuilt, underbuilt, or "engineered enough" before writing any code
Aggressively review test coverage, edge cases, and failure modes
Look for performance risks, scaling issues, and refactoring opportunities
But the real difference is the workflow.
Instead of jumping into implementation, he makes Claude:
Do a structured review (architecture → code quality → tests → performance)
Present tradeoffs with opinionated recommendations
Pause for feedback before proceeding
In other words, Garry is using it as a senior engineer reviewing the system before changes are made.
For small teams, this is a game changer. When you don't have a staff engineer reviewing every PR, you design the review process into your Al.