Lots of concepts. Release the harness that made it possible to port Bun to Rust in 9 days. That's what everyone really wants. Then everyone can go "do that but for this other goal".
There you have a verifier though. As in you have test cases (which are written in JS and thus do not need to be translated). The moment you have a verifier signal LLMs become extremely reliable. Now of course they can reward hack your test cases but in a large codebase with many tests it becomes the only small thing you have to worry about.