Diagnose Bug
Backend / algo / API root-cause with a repair hypothesis.
What it is
Section titled “What it is”Backend / algo / API root-cause with a repair hypothesis. This practice is a skill-mapped TTP: when, why, and which command—not a full copy of the skill. Open the skill to execute.
Why it works
Section titled “Why it works”Debugging without a hypothesis wastes time. This practice is the deterministic compute cut of diagnosis (Quality regimes A) — APIs, algos, pipelines — vs troubleshoot-app (product UI, B) or agents analyze + Langfuse (generative, C). Prefer the quality trace; silent data lies and missing contracts are still bugs.
When to use it
Section titled “When to use it”When the situation matches the one-liner above and Orientation (or your project path) says this is the fire to touch now.
- Invoke the skill; follow its safety rules
- Keep one write owner; collect evidence before claiming done
- Hand off to the next practice instead of boiling the ocean
- Skip orientation when you’re lost
- Spawn overlapping agents to “go faster”
- Treat the practice as done without evidence
Related concepts
Section titled “Related concepts”04-evidence-over-vibes, 11-quality-regimes, 12-bugs-and-debt, 13-quality-trace
Further reading
Section titled “Further reading”- Quality regimes (handbook)
- Google SRE Workbook — Implementing SLOs (correctness / pipeline SLIs)
- Google SRE — Monitoring distributed systems
- OpenTelemetry docs
See also the handbook Sources & grounding bibliography.
Agent skill
Section titled “Agent skill”diagnose-bug