The problem is you still think that the perfect prompt or AGENTS.md or whatever is going to get you a one-shotted (or close) feature in return. There isn't (yet) a model or orchestration framework that is going to take a large feature from start to finish for you.
The reality is that LLMs/agents are just a new way to write code. You still need to understand, more-or-less, how this feature is going to actually work, and how it needs to be implemented, from start to finish.
The difference is that you don't write the code, you tell the LLM to write the code. Once you've figured out the right "chunk size" an LLM can handle it's faster than doing it yourself.
I've found it's actually a little _harder_ in green field projects because the LLM doesn't have guard rails and examples and existing patterns to follow.
The reality is that LLMs/agents are just a new way to write code. You still need to understand, more-or-less, how this feature is going to actually work, and how it needs to be implemented, from start to finish.
The difference is that you don't write the code, you tell the LLM to write the code. Once you've figured out the right "chunk size" an LLM can handle it's faster than doing it yourself.
I've found it's actually a little _harder_ in green field projects because the LLM doesn't have guard rails and examples and existing patterns to follow.