AI Doubled Engineering Output But Review Never Caught Up
A longitudinal study of 802 developers and 196,212 pull requests at an enterprise AI mandate found per-developer throughput more than doubled — but human review coverage fell from 89% to 68% while silent, comment-free approvals held flat even as volume doubled. Automated review overtook human review, and reviewer load doubled alongside authoring output. For PMs, the lesson isn't that AI writes bad code — merge and revert rates barely moved — it's that authoring capacity and review capacity no longer scale together, and most teams haven't rebuilt review to match.