It's still shocking to me that the approach taken wasn't to have Claude write a tool that translates Zig to Rust. I imagine it would've been cheaper, deterministic, and each iteration would produce a better tool.

This seems like a much much harder problem than having a model translate between the two languages. I think people in general are way overvaluing determinism. In most cases, it doesn’t matter if the output from two runs is different as long as it accomplishes the desired goal.