Github Migrates Copilot Runtime to Rust with AI-Assisted Rewrite

GitHub completed a major migration of its Copilot runtime from TypeScript and Node.js to Rust using AI-assisted code rewriting, replacing over 800,000 lines of code in about 14.5 weeks. This change improved performance drastically, reducing startup times from 5.25 seconds to 292 milliseconds and enabling direct embedding into host applications without Node.js dependency.