Elevator Pitch

• Roc’s team has reached feature parity after a 1.5-year Rust-to-Zig compiler rewrite, unlocking new developer ergonomics and performance wins while reflecting candidly on tradeoffs vs. Rust.

Key Takeaways

• The new Zig-based compiler hit feature parity and already enables features like hot code loading, cross-compilation reproducibility, and allocation-free HTTP route matching via pattern interpolation.
• Zig’s strengths for Roc center on build tooling, allocator-centric APIs, and data-layout control; memory-safety outcomes so far have been acceptable, with most “memory corruption” reports being miscompilations rather than compiler bugs.
• Rust is still missed for some ergonomics (notably in tests, polymorphism traits, private fields, and backwards compatibility), but Zig is preferred overall for this project’s constraints.

Most Memorable Quotes

• “We recently passed an exciting milestone: feature parity with the original compiler!”
• “Not only is this type-safe at compile time, this entire code snippet performs zero heap allocations.”
• “zig build --watch -fincremental can rebuild a change to our current ~450K lines of Zig code in about 35 milliseconds.”