WHAT CAN WE LEARN FROM BUN'S RAPID RUST REWRITE WITH AI?

Summary from the TLDR newsletter

Bun was rewritten from Zig to Rust using Fable. A full rewrite would usually take too long, but the AI tool allowed it to be completed in 11 days. The project cost $165,000 with API pricing, consuming 5.9 billion uncached input tokens, 690 million output tokens, and 72 billion cached input token reads. The rewrite demonstrates how AI can now be cost-effective for codebase migrations when projects are well-engineered.