Well how did they rewrite it? If you do it in two phases, then it should be fine right?

Phase 1: extract requirements from original product (ideally not its code).

Phase 2: implement them without referencing the original product or code.

I wrote a simple "clean room" LLM pipeline, but the requirements just ended up being an exact description of the code, which defeated the purpose.

My aim was to reduce bloat, but my system had the opposite effect! Because it replicated all the incidental crap, and then added even more "enterprisey" crap on top of it.

I am not sure if it's possible to solve it with prompting. Maybe telling it to derive the functionality from the code? I haven't tried that, and not sure how well it would work.

I think this requirements phase probably cannot be automated very effectively.