AI makes these rewrites way, way easier than they used to be, but you do need to keep an eye on what they're doing
jerf on Hacker News
In the thread “AI changes the economics of software rewrites”, replying to this comment
Helped: Shared unit tests and side-by-side code comparison to verify feature parity.
Got in the way: AI silently dropped use cases and got confused by complex indirection.
… I did some work in creating unit tests that drew from a data source that both code bases could test against, since this was an HTTP API there was a relatively clean cut point for both codebases there. AI makes these rewrites way, way easier than they used to be, but you do need to keep an eye on what they're doing, cross-check the final output by hand or by those shared unit tests, and not just assume you can fire the project off Friday evening and take whatever it made by Monday because that end product is probably missing quite a few of the original features.