The Pulse: What can we learn from Bun’s rapid Rust rewrite with AI?

This article discusses the migration of the JavaScript runtime Bun from Zig to Rust, driven by persistent memory safety issues in Zig. The creator, Jarred Sumner, explains how memory-related bugs like leaks and crashes motivated the rewrite. The piece covers the role of AI-assisted tools like Fable in the migration, the challenges of mixing garbage-collected and manually managed memory, and the benefits of Rust's memory safety guarantees. It also touches on Bun's ecosystem impact, including its 22 million monthly downloads and adoption by tools like Claude Code. The article offers insights for senior engineers on language choice, stability, and leveraging AI in large-scale codebase rewrites.