AI-ENGINEERING
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    Loop Engineering

    AI Engineer path · lesson 86 of 124
    The idea
    Loop engineering is the difference between a junior who submits the first draft and a senior who runs the tests, reads the failures, fixes them, and only then calls it done — within a deadline, escalating if truly stuck.
    How to use
    Run a loop iteration, watch the agent self-check its output, and see how failure conditions trigger retry or escalation.
    TaskImplement parseDate() so all tests pass.
    attempt —
    GatherActVerifyretry on fail

    Run the loop — watch it verify, fail, and retry.

    Key insight

    The reliable loop adds a step ReAct skips: verify. Attempt 1’s tests failed, so the loop fed that failure back and retried — and attempt 2 passed. Self-correction comes from checking the work, not from the model getting it right first try.

    Keep an agent loop from running away

    Sort

    Sort each control by what it protects.

    Tap a piece, then tap where it goes — or drag it. Tap the tray to take one back.

    Guarantees termination

    Drop items here

    Limits the damage

    Drop items here
    6 pieces left to place

    Test your knowledge

    20 questions
    Question 1 of 20
    Score: 0

    What is the most effective way to retry after an agent's output fails verification?

    The short version

    Loop engineering is the difference between a junior who submits the first draft and a senior who runs the tests, reads the failures, fixes them, and only then calls it done — within a deadline, escalating if truly stuck.

    In more depth

    Loop Engineering

    Where context engineering manages the loop's inputs, loop engineering manages its control flow — making the agent loop reliable. The basic ReAct loop (think → act → observe) becomes production-grade by adding a verify step (tests, rules, or an LLM-judge), retry-with-feedback that appends the specific failure to context, and hard budgets (step/token/time caps + loop detection). A robust loop has four exits — success, budget exhausted, stuck, or escalate — and uses reliability patterns like sub-agents, parallel tool calls, checkpoints/idempotency, and graceful degradation.

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