21CTO

Jul 9, 2026 · Frontend Development

Bun’s 11‑Day, 780k‑Line Migration from Zig to Rust Powered by AI

In just 11 days, Bun migrated 1,448 Zig files and over 780,000 lines of code to Rust, achieving 100% test pass, cutting memory usage dramatically, reducing binary size by 20%, improving performance by up to 5%, and demonstrating an AI‑driven, fully automated rewrite that sparked intense community debate.