I have seen multiple people claim that {Copilot|Claude|a local Llama model} has been great for them at understanding large codebases, but at least to date, I have yet to actually have anyone provide a concrete example when I ask. Maybe others have a different idea of what constitutes "large."
At my job, our main repo is over 300k lines of just Ruby code, plus a bunch of JS, ERB templates, and other stuff. Every AI tool I've thrown at it is great at making surgical edits to single files (or small groups of files) but completely chokes if you ask it a question that requires it to understand context across the repo. I'm always hoping that I'm just using the tools wrong, but so far that doesn't seem to be the case.
