> how soon before we start designing codebases for LLM agents to navigate more cleanly?

In my (so far limited) experience, the best thing you can do is establish and consistently follow patterns in you handwritten code.

I find Claude does really well with “follow existing conventions and patterns” or pointing to some specific part of the app and saying “do it that way.”

I prompt Claude the same way I would a junior dev, and that seems to work really well so far.