What problem does it solve? Hard bugs and performance regressions stall when developers jump straight to hypotheses without a reproducible signal. This Skill enforces a disciplined diagnosis loop that builds a tight pass/fail feedback signal first, then reproduces, minimizes, hypothesizes, instruments, fixes, and cleans up. ## Core Features & Use Cases - Feedback loop construction: Ten ranked strategies for building a red-capable repro, from failing tests and curl scripts to headless browser runs, trace replay, fuzz loops, and git bisect harnesses. - Structured hypothesis testing: Generates 3-5 ranked, falsifiable hypotheses and maps each instrumentation probe to a specific prediction, changing one variable at a time. - Regression test discipline: Writes the regression test before the fix at a correct seam, then verifies with the original repro and removes all tagged debug instrumentation. - Use Case: A user reports that the export button intermittently throws an error. The Skill guides building a deterministic repro script, minimizing the failing scenario, testing ranked hypotheses, and landing a fix with a regression test. ## Quick Start Ask the agent to diagnose the bug where the export button throws an error and have it build a reproducible failing test before proposing any fix.
