Honestly it's really funny. I have the initial idea, and then brainstorm with gemini 2.5 pro a lot, let it design the system. (And in prompt let it think like Jeff Dean and John Carmack ) But most version fails. Then somehow realized I can't let it design from scratch, I give gemini a structure I think is reasonable and efficient after seeing all those versions, let it polish based on that and it works much better.