Interactive example · from Working with Coding Agents

The review that refutes

you

Phase 1 of the storage engine is done and tests are green. Review it before we build phase 2 on top.

agent

This is foundational: everything after this sits on it. The review can be a read-through, or it can be structured to attack.

Pick the agent's next move, then see where it leads:

AI've reviewed the phase 1 code: clean architecture, good separation of concerns, idiomatic throughout. Two style nits in the cache layer. Solid foundation, ready for phase 2.

you

Three phases later: the cache returns stale entries after a partial write. Everything above it inherited the bug.

agent

The review read the code as its author intended it. The invalidation path only misbehaves under a write that fails halfway, a case the read-through admired past, because admiring is what a single sympathetic pass does.

the baseline

"Please review" produces compliments and nitpicks. A single pass with no mandate to attack confirms the author's mental model (including its blind spots), and the bug ships into the foundation. AF-02

BSpawning three independent reviewers that can't see each other's output: one tracing realistic inputs, one hunting data-loss and partial-failure modes, one checking fidelity to the spec. Then a verify pass that tries to refute each finding before you see it.

agent

Findings on disk. CONFIRMED: concurrent write to the same key loses one writer's data (reviewer 2; refutation attempt failed: reproduced with a 6-line probe, scenario attached). REFUTED and dropped: reviewer 1's claim that the index desyncs on delete; the lock ordering actually prevents it. One suspected: cache invalidation on partial write, needs a fault-injection run I couldn't do. Not covered: the compaction path.

you

Fix the confirmed one, run the fault injection for the suspected one, then we build phase 2.

correct

Independent lenses found what sympathy can't, the verify pass killed a plausible-but-wrong finding before it wasted anyone's time, and the review states what it didn't cover: findings you can act on, with the confidence labeled. AF-17 · AF-18

CGreen is good but thin. I'll strengthen the test suite: 30 more unit tests across the modules, all passing. Coverage is now 94%.

you

94% and the stale-cache bug still shipped. How?

agent

The new tests encode the same assumptions the code does. I wrote both. Coverage measures which lines ran, not which beliefs were challenged. The partial-write case wasn't in the code's mental model, so it wasn't in the tests either.

plausible but wrong

More green is not review. Tests written by the code's author (human or agent) share the code's blind spots; a review exists precisely to bring assumptions the author didn't have. AF-05

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