- The author developed a Rust-based PHP interpreter called Phargo without knowing Rust, relying on AI to write the code.
- The project uses PHP's official 22,000-file test suite as an unbiased oracle to validate correctness and measure progress.
- The author's role is minimal: directing the AI to fix failing tests, running the test suite, and committing improvements.
- Initial issues included undetected failures due to CRLF line endings in tests, highlighting the importance of accurate measurement.