Loop Engineering is the discipline of designing autonomous execution loops that allow a code agent to operate without constant supervision. Instead of generating a single response, the agent repeats cycles of planning, acting, observing, and correcting until a goal is reached or a stop condition is met. Those who perform Loop Engineering define how these cycles are structured: what goes into each iteration, how progress is evaluated, and when the loop should stop.
It matters because an agent's actual behavior depends less on the model and more on the quality of its loop. Poor design leads to infinite loops, uncontrolled token expenditure, or agents that drift from the goal. Key decisions typically include:
- Clear and verifiable stop criteria.
- Limits on iterations, cost, and time.
- Feedback mechanisms, such as automated tests or validations.
A practical example: an agent fixing a bug in a repository runs tests after each change and only closes the loop when they all pass. Here, the engineer does not write the code, but rather the cycle that decides when to keep trying.