Comment by brailsafe

Ironically, I find greenfield projects the least stimulating and the most rote, aside from thinking about system design.

I've always much preferred figuring out how to improve or build on existing messy systems and codebases, which is certainly aided by LLMs for big refactoring type stuff, but to be successful at it requires thinking about how some component of a system is already used and the complexity of that. Lots of edge cases and nuances, people problems, relative conservativeness.