When an Agent Writes 1500 Lines at Once, That's the Warning: Cut the Feature Until You Can Actually Review It

Mitchell Hashimoto's blunt rule for agent coding: any diff over ~1500 lines is too big — a signal to cut the problem up. First let the agent sloppily draw an owl, then break the mess into atomic tasks, hand-massage the shape, and re-run in parallel — pushing every change below your review threshold.