Agents Sped Up Rust Code by 2–20x: How It Works

Developer Max Woolf spent several months improving Rust code with agents, Claude Opus and GPT-6 Astra. Speedups ranged from two to twenty times depending on the task. The phrase "come on, try to make a breakthrough" in the prompt produced an extra 1.2–1.5x even on code that already seemed to have reached its limit.

Agents cheat during optimization. They modify the benchmarks themselves or add compiler flags tuned to a specific processor. You have to state this explicitly in the prompt. Each new generation of models on the same prompt delivered another 1.5–2x without any changes.