Root-Cause Investigation
Debug a defect or production incident down to its true root cause and document the diagnosis with evidence, instead of patching the first symptom. First reproduces the failure reliably and locks what 'understood' means (a confirmed repro, the failing assertion, the exact trigger condition), then narrows the cause by forming and testing hypotheses, bisecting, reading stack traces and logs, and tracing the data path until one hypothesis is proven, then writes a root-cause report with the evidence chain, the smallest fix, and how to prevent recurrence. Use this for debugging, root-cause analysis, investigating a bug or flaky test, diagnosing an incident, or figuring out why something breaks — it produces a proven cause backed by evidence, not a guess.
How it runs
| # | Step | Who runs it | What happens |
|---|---|---|---|
| 1 | Reproduce & scope | Reviewer | get a reliable repro, lock what 'understood' means |
| 2 | Narrow the cause | Reviewer | form + test hypotheses until one is proven |
| 3 | Write the root-cause report | Reviewer | diagnosis, evidence chain, smallest fix, prevention |
| 4 | Evaluate | Reviewer | Grade the deliverable against every acceptance criterion. All pass → finish; any fail → loop back and fix the gap. |
| 5 | Finish | Developer | All acceptance criteria met. Stamp a short summary and report DONE. |
Say something like "investigate this bug" or "root cause this" or "why is this failing" or "debug this" or "figure out why it breaks" or "diagnose this incident" in chat to start it.