Yeah, I think monorepos are pretty great. Sometimes not possible, but for those situations you just need to have a way for the agent to get access to other codebases (gitlab mcp being what I rely on at work).

I don't think you need more documentation or these memory systems. The code IS the documentation. Lots of this stuff is unnecessary. It's a bunch of people doing their special rain dances and then when it happens to rain they say "I did that"