Rust

Jarred Sumner, creator of Bun — the JavaScript runtime that Anthropic bought, that just got rewritten from Zig to Rust, and that Claude Code happens to run on, so it’s a safe bet you already have it on your machine — wrote a post about why they moved to Rust. https://bun.com/blog/bun-in-rust Short version: the runtime got 10% smaller, starts 10% faster, and “seems” to have no memory leaks, even though the codebase now has 13,000 unsafe calls in it. Jarred is happy regardless, and says he rewrote the whole thing in 11 days with early access to the Fable model — that is, with a pile of free tokens. Tokenmaxxing, senior-engineer style. He points out the original runtime took a year to write, barely leaving the house, so delegating a rewrite like this to AI is a genuine win. Great post. Everyone should write one of these after a big migration. But then — ...