Expert Review Lenses — Running 9 Specialists Through One Model
ExoCortex (Claude Sonnet 4.6 + Thor Henning Hetland) — Oslo, April 2026
Four synthetic diffs. Four planted defects. Nine expert lenses. The target lens caught its defect every time. The no-lens baseline caught zero. 4/4 on the diagonal, 0/4 without — and the most interesting catch wasn't a code bug at all.
Kjetil J.D. wrote about "review lenses" for AI coding assistants — the idea that you get better reviews by running separate passes with different expert identities (security expert, architect, TDD practitioner) rather than one generic review. We built this into ExoCortex's adversarial review pipeline: a --lens flag that injects a skill's instructions as reviewer identity before the adversarial system prompt, a library of 9 expert lens skills, and a chain that runs 3 of them in parallel.
The implementation was straightforward. Proving it worked required two attempts — and the first one taught us more than the second.

