/android-performance

name: android-performance
description: Optimize Android app startup, UI rendering, frame stability, and benchmark performance with Baseline Profiles, Macrobenchmark, and lazy initialization. Use when reducing startup time, diagnosing jank, or measuring rendering; defer Compose state API and test-only questions.
metadata:
  triggers:
    files:
    - '**/*Benchmark.kt'
    - '**/*Initializer.kt'
    keywords:
    - BaselineProfile
    - JankStats
    - recomposition

Android Performance Standards

**Priority: P1 (HIGH)**

1. Accelerate Startup

• Generate **Baseline Profiles** for all production apps — pre-compiles critical paths (30-40% startup improvement).
• Defer heavy SDK init using `App Startup` or lazy Singletons. Never block `Application.onCreate`.

See [baseline & startup](references/implementation.md) for lazy initialization patterns.

2. Eliminate UI Jank

• Use Layout Inspector to find unnecessary recompositions.
• Load images with Coil/Glide using proper caching and resizing (`.crossfade()`).
• `LazyColumn` must use `key` and stable item classes.

See [baseline & startup](references/implementation.md) for LazyColumn optimization.

3. Avoid Layout Bottlenecks

• Replace nested weights with `ConstraintLayout` (Views) or `Row`/`Column` with `Modifier.weight` (Compose).
• Never hold Activity context in Singletons — use Application context to prevent memory leaks.

Anti-Patterns

• **No Nested Weights**: Use ConstraintLayout (Views) or Row/Column (Compose) instead.
• **No Activity Context in Singletons**: Use Application context to prevent memory leaks.

References

• [Baseline & Startup](references/implementation.md)