07-21
How to Build the Loops That Just Replaced Entire Prompt Engineering
The era of crafting better prompts to improve AI agents is quietly ending. Top engineers now build 'loops'—systems where agents plan, execute, verify, and iterate without human intervention. Using Karpathy's overnight 700-experiment run that found 20 optimizations as a case study, the article breaks down loop architecture: automation heartbeat, skill files (project context), sub-agents (writer vs reviewer), connectors, and a verifier gate. It warns against Ralph Wiggum loops (premature exit) and comprehension debt (accumulated unread code). Practical advice: start with one boring recurring task, verify manually before scheduling, measure cost per accepted change. Essential for engineers building production agent workflows.