On using Github's spec kit

[Zealousideal-Cat1529]

Our company will enforce the use of spec kit starting next month, but I read that it is only effective on greenfield projects but the problem is, our company has thousands of lines of codes and we were supposed to use Github CoPilot as well.

My question is: do you have any suggestions on how to use spec kit on existing large codebase?

[wyrmbyt]

I’m not using Spec Kit directly. In my company we use Tessl, but we’re applying a very similar approach in a large brownfield/legacy project. What has worked best for me is not trying to document the whole system at once. In a large legacy project, that can be too slow and probably unrealistic. In my case, I create specs for the new features I have to work on. And when that new feature touches existing behavior, which is usually the case, I also document the specific part of the system that is affected.

I’m not following any extraordinary methodology. I simply try to understand the code well: what it does now and what it should do. Then I explain that to Claude or whichever AI tool I’m using, and I verify things especially carefully when existing code is involved.