We 3.5x’d Our Pull Requests with AI: Now We Catch Fewer Bugs

I made a few claims in the past stating that the average size of pull requests went up by an order of magnitude. I largely based it on hallway conversations with developers at Lunar Logic. It turns out, the actual data is not that hard to check. Aaaand I was wrong. AI Effect in PR Size We pulled data from two very similar projects in terms of complexity, effort, and team size. Both codebases started greenfield and covered a few hundred pull requests in the analyzed period. There was even an overlap across the engineering team. The key difference? How we used AI. The first project, let’s call it Helpful, happened in the pre-Claude era. While we already used AI to support development, it was predominantly autocomplete with occasional trips to ChatGPT to suggest solutions to pesky problems. All code was managed by developers in real time. The second gig, I’ll call it Grateful, was full-on Claude. The basic assumption was that none of the code was written by hand. Engineering…