Mobile app performance optimization encompasses strategies and techniques for improving startup time, memory efficiency, battery consumption, network usage, and UI responsiveness across iOS and Android platforms. Performance directly impacts user retention—53% of users abandon apps that take longer than 3 seconds to load—making optimization essential for app success. The key mental model is to understand that mobile devices have constrained resources (CPU, memory, battery) compared to desktop systems, requiring developers to prioritize critical paths, defer non-essential work, and aggressively optimize the most common user flows rather than attempting to optimize everything equally.
What This Cheat Sheet Covers
This topic spans 15 focused tables and 148 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: App Startup Optimization Techniques
| Technique | Example | Description |
|---|---|---|
Defer non-critical initialization: Application.onCreate() { // Critical only initCrashReporting() // Defer analytics, ads} | • Fastest startup type from when app process doesn't exist • minimize work in Application.onCreate() or application(_:didFinishLaunchingWithOptions:) to achieve sub-2-second cold starts | |
Preserve activity state: onSaveInstanceState(Bundle) | • App process exists but activity needs recreation • optimize by caching frequently-used data in memory and avoiding redundant initialization — typically 50-70% faster than cold start | |
private val analytics by lazy { AnalyticsSDK.create()} | • Initialize objects only when first accessed, not during app startup • reduces initial memory footprint and CPU usage during critical launch phase | |
class WorkManagerInitializer : Initializer<WorkManager> | Jetpack library that coordinates initialization order and provides single ContentProvider entry point, eliminating multiple ContentProvider overhead that can add 50-100ms per provider | |
splashScreen.setKeepOnScreenCondition { !viewModel.isReady.value} | • System-level splash screen API introduced in Android 12 • ensures instant app launch animation while app initializes in background |