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 ordered strategies for building a red-capable test signal, from failing tests and curl scripts to replayed traces, fuzz loops, and git bisect harnesses. - Structured hypothesis testing: Generates 3-5 ranked, falsifiable hypotheses before testing, with one-variable-at-a-time instrumentation and tagged debug logs for clean removal. - Regression and post-mortem discipline: Writes regression tests at correct seams before fixing, verifies the original repro, removes instrumentation, and captures the root cause in the commit message. - Use Case: A user reports their API endpoint intermittently returns wrong data. The Skill guides building a deterministic failing test, minimizing the repro, ranking hypotheses, instrumenting with tagged logs, and landing a fix with a regression test. ## Quick Start Ask the assistant to diagnose the bug you are experiencing and describe the exact symptom, error message, or slowdown you observed.
