alt Hacker NewsSomething in this realm covers my practice. I just keep a master prompt for the whole program, and sparsely documented code. When it's time to use LLM's in the dev process, they always get a copy of both and it makes the whole process like 10x as coherent and continuous. Obvi when a change is made that deviates or greatly expands on the spec, I update the spec.
I do something similar with quality gates. I have a bunch of markdown files at the ready to point agents to for various purposes. It lets me leverage LLMs at any stage of the dev process and my clients get docs in their format without much maintenance from myself. As you said once you get it down it becomes a very coherent process that can be iterated on in its own right.
I am currently fighting the recursive improvement loop part of working with agents.