The problem with an AI-built codebase is not the mess. It is that nobody has read it.

When people talk about taking over a vibe-coded project, they expect a mess. That is usually not what is there. The formatting is consistent, the names are reasonable, and it runs.

The problem is a different one. Nobody has read it, including the person who shipped it. So the same logic turns up in more than one place. The agent wrote it fresh each time instead of finding what was already there. And there is no record of why anything is the way it is.

The first thing I do is not clean that up. I make it so I can tell when it breaks. Until you have that, every change you make is a guess.

If you have taken over an AI-built project, what is the first thing you open?