Bun Is Rewriting Its Code (It's bad)

Bun is rewriting its entire Zig codebase in Rust, with the migration reportedly completed in under 7 days using LLMs. Bun 1.3.14 is expected to be the last Zig-based release. The author acknowledges the memory safety benefits of Rust over Zig (particularly around use-after-free bugs and segfaults) but raises concerns about shipping an LLM-generated million-line rewrite to production quickly. Key worries include the 0.2% failing tests, unknown new bugs introduced by the rewrite, and Bun's existing stability track record with 5,000+ open issues. The author personally recommends against using Bun for high-traffic production backends, suggesting Node.js with esbuild or TSX instead.