compose-performance-audit

Compose Performance Audit

Overview

Audit Jetpack Compose view performance end-to-end, from instrumentation and baselining to root-cause analysis and concrete remediation steps.

Workflow Decision Tree

• If the user provides code, start with "Code-First Review."
• If the user only describes symptoms, ask for minimal code/context, then do "Code-First Review."
• If code review is inconclusive, go to "Guide the User to Profile" and ask for Layout Inspector output or Perfetto traces.

1. Code-First Review

Collect:

• Target Composable code.
• Data flow: state, remember, derived state, ViewModel connections.
• Symptoms and reproduction steps.

Focus on:

• Recomposition storms from unstable parameters or broad state changes.
• Unstable keys in LazyColumn/LazyRow (key churn, missing keys).
• Heavy work in composition (formatting, sorting, filtering, object allocation).
• Unnecessary recompositions (missing remember, unstable classes, lambdas).
• Large images without proper sizing or async loading.
• Layout thrash (deep nesting, intrinsic measurements, SubcomposeLayout misuse).

Provide:

• Likely root causes with code references.
• Suggested fixes and refactors.
• If needed, a minimal repro or instrumentation suggestion.

2. Guide the User to Profile

Explain how to collect data:

• Use Layout Inspector in Android Studio to see recomposition counts.
• Enable Recomposition Highlights in Compose tooling.
• Use Perfetto or System Trace for frame timing analysis.
• Check Macrobenchmark results for startup/scroll metrics.

Ask for:

• Layout Inspector screenshot showing recomposition counts.
• Perfetto trace or System Trace export.
• Device/OS/build configuration (debug vs release).

Important: Ensure profiling is done on a release build with R8 enabled. Debug builds have significant overhead.

3. Analyze and Diagnose

Prioritize likely Compose culprits:

• Recomposition storms from unstable parameters or broad state changes.
• Unstable keys in lazy lists (key churn, index-based keys).
• Heavy work in composition (formatting, sorting, object allocation).
• Missing remember causing recreations on every recomposition.
• Large images without Modifier.size() constraints.
• Unnecessary state reads in wrong composition phases.