Power Bug Triage: Interview Drills

Interview drills

Interview Drills for Power Bug Triage is anchored on illegal transition rate, corruption incidence, and deterministic replay quality under low-power scenarios. Convert observations into mechanism-backed and owner-bound actions.

PROMPT
You observe regression in illegal transition rate, corruption incidence, and deterministic replay quality under low-power scenarios for Power Bug Triage. Explain root cause and release decision.

STRONG ANSWER
1. Defines failing phase and workload context.
2. Explains mechanism: Low-power bug triage must start from first power-intent divergence, not the final scoreboard mismatch, because symptoms can appear thousands of cycles after the causative transition. Practical triage stacks evidence in layers: power controller command and acknowledge timeline, domain/supply state traces, isolation and retention control behavior, then protocol and functional fallout. Classifying defects early into sequencing, intent-binding, structural insertion, or software orchestration issues avoids expensive cross-team ping-pong and speeds owner routing. Strong teams maintain reproducible minimal tests for each bug class and track escape patterns such as intermittent wake-up corruption, stale retained state, or cross-domain deadlock that only occurs under concurrent traffic and power events.
3. Requests proving artifact: evidence packet for Power Bug Triage: transition timeline, assertions, and before-after replay summary
4. Proposes bounded fix + owner + rollback-safe validation.

WEAK ANSWER
Gives generic low-power advice without mechanism proof, evidence, or ownership.

Low-power verification deep dive

Signoff confidence comes from triage discipline, reproducible proof, and explicit residual-risk decisions.

Concept diagram

LPV SIGNOFF LADDER

reproduce -> classify -> isolate boundary -> bounded fix -> replay -> signoff decision

Metric graph

SIGNOFF CONFIDENCE

open ambiguous failures  ██████
reproducible closures    ███████
residual-risk unknowns   ███

Metrics and artifacts to collect

• X-prop triage classification report

• bug root-cause closure packet

• regression stability and recurrence trend

• signoff checklist completion matrix

Mini case study

A signoff block cleared after the team replaced broad waivers with boundary-specific evidence and replay criteria.

Debug branches

• Classify X behavior before broad waiving.

• Capture one definitive artifact packet per closure claim.

• Define residual risk and rollback path at signoff.

Senior review question

Ask: what exact low-power transition boundary failed first, and which artifact proves the closure claim reproducibly?

Key takeaways

• Tie each LPV claim to a concrete transition boundary and one proving artifact.

• Prefer minimal reversible fixes with explicit owner and rollback criteria.

Common pitfalls

• Treating power-aware failures as random before boundary classification.

• Waiving X-prop failures before proving impact and root cause.

• Declaring closure without deterministic replay across key modes.

Principal LPV review addendum

Power Bug Triage should be reviewed as a transition integrity system, not just isolated checks.

Use illegal transition count, corruption incidence, and reproducibility of low-power regressions across fixed seeds as alarm and LPV evidence packet: transition timeline, assertion outcomes, and before-after replay summary as proof.

LPV debug and signoff require disciplined triage: classify X behavior, isolate root cause, and close with reproducible evidence. Closure quality comes from reproducible evidence and explicit owners.