Bun rewrites core in Rust with Claude, fixes bugs and cuts binary size

Bun has migrated its core from Zig to Rust using Anthropic's Claude LLM-powered workflows, addressing many stability issues in the process.

The Rust rewrite fixes 128 reproducible bugs from earlier versions, including several memory leaks and crashes. Users will also see a 20% reduction in binary size and lower memory usage during builds.

The team employed an adversarial, multi-agent review system to complete the rewrite in under two weeks.