Hacker News — 2026-07-09#

Top Story#

The biggest explosion on the front page today surrounds the dramatic codebase shift of the Bun runtime. Jarred Sumner published a massive post detailing how they leveraged Anthropic’s Claude to rewrite Bun from Zig to Rust in just 11 days, utilizing dynamic workflows and adversarial agent reviews. The post is a fascinating technical case study on agentic engineering, but the real firestorm ignited when Andrew Kelley, creator of Zig, published his own unfiltered thoughts on the rewrite. Kelley blasted Bun’s management and previous Zig code quality, essentially saying the Zig team is relieved that Bun and its “slop” are no longer their problem. It’s a rare, highly public clash between a major language creator and one of its highest-profile users.