You Have a Review Ceiling. Measure It Before It Measures You.

I sat in on Margaret-Anne Storey's DORA community session last week, and she put a name on the thing I'd been circling since April. It isn't technical debt. Her ACM Queue piece splits software health into three debts. Technical debt is the familiar one: implementation choices that make tomorrow's change harder. Intent debt is the missing rationale, the goals and constraints that say what a system is even for, which now has to be legible to agents and not just to people. Cognitive debt is the one that stopped me. It's the erosion of shared understanding, the state where nobody on the team can confidently explain how the system works or predict what a change will break. Read that again if you review pull requests for a living. I closed a thirteen-post retrospective last month admitting I couldn't answer one question: how many AI-generated pull requests a week can a review process absorb before it stops working as a control? I still don't have that number. What I have now is a name for what you accumulate while you don't have it, and a way to find yours. Approval velocity measures motion Every metric most teams watch gets better as review collapses. Merge rate climbs. Time-to-approve drops. The throughput chart looks terrific right up until the incident review, because a reviewer who has quietly become a rubber stamp is indistinguishable from a fast reviewer in every dashboard you own today. Cognitive debt doesn't announce itself as a red number. It shows up as green ones, arriving faster. I know this failure mode from the inside. Two months of green CI on conformance checks that had never once passed , on my own project. A human audit caught it. No metric I was watching came close. What you need to measure is detection. Almost nobody does. Mutation testing, pointed at the reviewers We solved this once already, for test suites. Mutation testing injects known bugs into code and checks whether the tests catch them. A suite that passes everything might be thorough or migh