diagnose

A systematic debugging loop diagnoses hard bugs through structured phases: reproduce, hypothesize, instrument, fix, and regression test. This disciplined workflow creates deterministic, reproducible signals that guide fixes and keep debugging efforts auditable and science-based.

To find the root cause of a performance regression, build a reproducible test setup, form a hypothesis, instrument the code for fail-fast signals, and verify the fix. Staged hypothesis testing ensures experiments remain deterministic and auditable throughout the diagnosis process.

The best way to reproduce bugs for root-cause analysis is to build repeatable test setups that generate fail-fast signals. Using structured phases and logs tagged with unique prefixes keeps debugging experiments deterministic and provides clear, reproducible loops for identifying root causes quickly.

Yes, you can use this debugging workflow for both unit tests and end-to-end scenarios. The structured phases of reproducing, hypothesizing, instrumenting, fixing, and regression testing apply across debugging tasks, using fail-fast signals and staged hypothesis testing to guide fixes in any context.

Instrumentation and checkpoints keep bug diagnosis auditable by enforcing explicit success criteria and tagging logs with unique prefixes. This disciplined feedback loop ensures every experiment remains deterministic, traceable, and science-based from initial reproduction through final regression testing.

You should avoid a structured debugging loop when a bug is trivial or immediately obvious from a quick code review, as the overhead of formal reproduction, hypothesis testing, and instrumentation is designed for hard bugs and complex performance regressions requiring deterministic, auditable investigation.