iOS App Lifecycle

Priority: P0

Implementation Workflow

1. Configure SceneDelegate — Use for UI windows and scene-specific state in iOS 13+.
2. Keep AppDelegate slim — Focus on app-wide setup (DI, Analytics, Push registration). Move initialization logic to a dedicated Bootstrapper or AppCoordinator.
3. Handle deep links — Prefer Universal Links over custom URL schemes. Handle via scene(_:continue:userActivity:). Route through the Root Coordinator.
4. Schedule background tasks — Use BGTaskScheduler for periodic data refresh. Always handle expirationHandler to avoid system kill.

See bootstrapper pattern and background task examples

Anti-Patterns

• ❌ Complex logic in didFinishLaunchingWithOptions — delegate to a Bootstrapper service
• ❌ UIWindow setup in AppDelegate — use SceneDelegate for iOS 13+
• ❌ Synchronous network calls during launch — move to background thread

References

• Lifecycle & Background Tasks