android-performance-observability（Android 性能可观测性）

Android Performance Observability

When To Use

• Use this skill when the request is about: android performance profiling, baseline profile or macrobenchmark, app startup issue android.
• Primary outcome: Measure startup, rendering, memory, jank, vitals, logs, and crash signals for Android apps with actionable traces.
• Read references/patterns.md when you need the measurement ladder for startup, jank, traces, and production signals.
• Read references/scenarios.md for repeatable profiling and trace-oriented entry points.
• Handoff skills when the scope expands:
• android-compose-performance
• android-ci-cd-release-playstore

Workflow

1. Classify the symptom before choosing tools: cold start, warm start, frame/jank, scrolling, memory, ANR, crash, battery, or production vitals drift.
2. Measure on release-like builds and physical devices whenever possible; avoid debugging from debug-only traces or profile-unfriendly builds.
3. Pick the smallest tool that answers the question: Macrobenchmark for startup/scroll numbers, Baseline Profiles for ahead-of-time optimization, Perfetto/System Tracing for deep traces, JankStats or FrameMetrics for frame quality, and Play Vitals for field evidence.
4. Change one thing at a time, then compare before and after traces or benchmark outputs instead of stacking multiple optimizations blindly.
5. Hand off UI-specific rendering changes or release rollouts only after the measurement surface is stable and the bottleneck is evidenced.

Guardrails

• Treat benchmarks, traces, and vitals as different evidence sources with different noise profiles; do not mix them casually.
• Prefer reproducible release-build measurements over debug-build intuition.
• Tie optimizations back to user-facing metrics such as startup time, frame pacing, ANRs, or battery impact.
• Keep the profiling setup stable enough that regressions are attributable to code changes instead of device or environment churn.

Anti-Patterns

• Chasing micro-optimizations before identifying whether the problem is startup, rendering, I/O, or field reliability.
• Reading one noisy trace and presenting the result as settled fact.
• Measuring debug builds and assuming the same behavior in production.
• Adding Baseline Profiles or macrobenchmarks without checking whether the target path is stable enough to compare.

Review Focus

• Startup: cold and warm launch, expensive initialization, and Baseline Profile coverage.
• Rendering: jank, skipped frames, Compose or View invalidation churn, and long main-thread work.
• Memory and reliability: allocations, leaks, ANRs, crashes, and Play Vitals trends.
• Evidence quality: repeatable commands, release-like variants, and documented before/after comparisons.

Examples

Happy path

• Scenario: Audit the repo for profiling surfaces and benchmark-related hooks before proposing a measurement plan.
• Command: rg -n "baseline|macrobenchmark|profileable|JankStats|Trace|Perfetto".

Edge case

• Scenario: Keep startup and rendering investigations grounded in repeatable release-like builds.
• Command: cd examples/orbittasks-compose &&./gradlew:app:assembleDebug

Failure recovery

• Scenario: Keep observability requests distinct from Compose-only tuning or release automation.
• Command: python3 scripts/eval_triggers.py --skill android-performance-observability

Done Checklist

• The bottleneck is classified and tied to an evidence source that can be re-run.
• The chosen tools match the symptom instead of duplicating noisy measurements.
• Before/after comparisons are explicit for any recommended optimization.
• UI-only or release-only work is separated from measurement and tracing.

Official References

• https://developer.android.com/studio/profile/overview
• https://developer.android.com/topic/performance/vitals
• https://developer.android.com/topic/performance/benchmarking/macrobenchmark-overview
• https://developer.android.com/topic/performance/benchmarking/macrobenchmark-metrics
• https://developer.android.com/topic/performance/baselineprofiles/overview
• https://developer.android.com/topic/performance/tracing
• https://developer.android.com/topic/performance/rendering/jankstats