Improve Android App Screen Launch Times Using LazyLifecycle Callbacks
Article Summary
Microsoft Teams Android engineers faced a critical problem: heavy initialization code in lifecycle callbacks was killing app launch times. Their solution? Get lazy.
The Microsoft Teams Android team built LazyLifecycle Callbacks, a framework that defers non-critical initialization until after the screen renders. Instead of blocking the main thread during onCreate/onResume, they wait for the UI to draw before executing expensive operations.
Key Takeaways
- P95 warm launch improved 24%, cold launch improved 12%
- Uses Barrier construct to delay code until N draws or SLA timeout
- Defers RN engine warmup, telemetry, prefetches without blocking render
- Open sourced framework handles state management and concurrency automatically
Critical Insight
By deferring non-critical initialization until after screen render, Microsoft Teams achieved double-digit improvements in Android launch performance.
