I have a hard time finding concrete examples that does not breach contract of dox me.

I feel like this issue goes beyond a single large legacy codebase. It can go beyond how the code works into what the code does. How should a thing behave may itself be institutional knowledge only Bary that was involved in the design process still remembers.

Pointing an agent at a problem in one codebase to write a patch can work quite well. But what do i do when the problem is either in the tool, the database, or the two API layers between? You may not even have the code for half of it as it's part of another department or externally purchased solution.

Bary would know, or know who to talk to, or dig up a PowerPoint slide he's been working on to explain it.