Hopefully they have a test suite written by QA otherwise they're for sure going to have a buggy mess on their hands. People need to learn that if you must rewrite something (often you don't actually need to) then an incremental approach best.
1 month of Claude Code would be an incremental approach
It would honestly try to one-shot the whole conversion in a 30 minute autonomous session
> often you don't actually need to
Feels like this one is always a mistake that needs to be made for the lesson to be learned.