Bun, a modern JavaScript runtime built with Zig and JavaScriptCore, achieves remarkable performance in microservice benchmarks, ranking 4th overall with a 157ms mean response time and 6,400 requests/sec—competing directly with Rust frameworks. It outperforms Node.js/Express.js by 5x in response time and 10x in successful requests per second, maintaining 100% stability under load. The performance stems from JavaScriptCore's optimization, native HTTP server implementation, io_uring for async I/O, and zero transpilation overhead for TypeScript.