“Zig’s 35ms is still way ahead… 1/100th the build time of 3.4 seconds.”
The Roc team spent 487 days rewriting a 300,000-line compiler from Rust to Zig and just got back to feature parity. They traded Rust’s memory safety for faster builds and an architecture they could actually finish. The real driver was buried in the middle: lambda set resolution was “incredibly difficult for us to implement correctly” in the old design. That is over a year of work to return to where you started, on a bet that the next mile is easier.