Mobile App Launch Profiling
Article Summary
Andrew McKnight from Sentry just solved one of mobile performance monitoring's biggest blind spots. Ever wondered what's actually happening in your app before main() even gets called?
Sentry's engineering team has shipped app launch profiling for iOS and Android, capturing performance data from the moment your app starts executing code. This goes beyond Apple's MetricKit and Instruments by profiling the critical pre-main() execution phase that traditional tools miss entirely.
Key Takeaways
- Profiles app execution before main() and appDidFinishLaunching where SDKs typically initialize
- Captures work hidden from Apple's MetricKit like splash screens and loading states
- Enable with SentryOptions.enableAppLaunchProfiling for automatic subsequent launch profiling
- Integrates with Time to Full Display tracing for complete app start insights
Critical Insight
You can now profile real user app launches from the very first line of code execution, revealing performance issues that Apple's own tools don't measure.
