There's no reason for software to be slow anymore

With LLM agents, performance optimizations that took days now take minutes.

Dan Luu argues that LLM coding agents have collapsed the human time and expertise needed for performance optimization, making formerly expensive work cheap enough for personal projects. He describes workload-specific regex optimization: a version of his FRE engine, optimized via agent for his own ripgrep queries, showed a 2% speedup on a holdout set after minutes of human time. He also built a world-leading Azul AI via agent, where multi-threading and other optimizations would have taken days by hand. He notes that dynamic, workload-fitted software is becoming feasible for larger companies as well.