Hi! We address this question in our FAQ and probably could do a longer blog post about our experience after we are further along: https://pyrefly.org/en/docs/pyrefly-faq/#why-rust
I'm sure you had reasons to do it this way. But given sufficient time to market, implementing the algorithm in pyre and then tooling/llm assisted conversion to pyrefly would've been preferable.
May be you'd have had some humans in the loop initially. But that tech is getting better and aligned with the direction Meta and the rest of the industry are taking.
Yes, I'm biased :)
Is this how it is now? Not the first time I hear this brainrot idea.