Do you know anything about your codebase? How?

Generally, I know a LOT about my team's code, and then in concentric circles I know less and less of the periphery. I work on <feature X> and know almost everything. That's a subsystem of <project Y> which I know well. That's part of <product Z> which I know in varying amounts.

And of course, there are things like build systems (CMake, ninja, blaze) where I know the basics, but I've never been an expert and don't care to be. Before I'd offload build features to another team; now I'd offload it to an AI. It's not something I need to be an expert in. I just want builds to work well.