Catching Bugs Before They Land: JiTTesting’s Human-on-the-Loop Approach at Full Scale

Our short summary of Meta’s engineering write-up. The full story, with all the detail, is on their blog.

Problem

Code changes introduced bugs faster than traditional tests could catch, risking production issues.

They built a system that uses LLMs to automatically write tests for each code change and an LLM‑as‑judge ensemble to filter out false positives.

Want the architecture, code and numbers? They’re in the original post.