Part of "AI, engineering and what survives production", a series on the parts of building with AI that hold up once real traffic hits them.
There is a claim going round that you have probably absorbed by now: AI-assisted development is making codebases worse. Refactoring is down, duplication is up, we are all writing more and revising less. The numbers behind it are real, the samples are enormous, and I found I had started repeating the conclusion in conversation without ever having checked it.
Then it occurred to me that those figures are averages taken across hundreds of millions of changes from thousands of organisations, not one of which is mine. So what is the rate in your repository? Nobody has told you, and on current evidence nobody is going to. I set out to find mine, assumed it would take an afternoon, and spent three days discovering that the answer is far harder to get at than the confident version suggests.
So this is not a piece about what AI does to code. It is about how to ask that question of your own repository without arriving at a wrong answer, which turned out to be the genuinely difficult part. The tool I built to do it is git-habits: free, local, and it reads no source code whatsoever.
