App Startup API: Speed Up Your Launch in 5 Minutes 🚀

Nobody likes waiting for apps to open. On Android, every extra millisecond at startup can hurt retention. That's where the Jetpack App Startup API comes in—it simplifies how you initialize components on launch.

The Old Way 😬

Before App Startup, we'd stick initialization code in Application.onCreate() or use ContentProviders. Messy, hard to manage, and slowed down cold starts.

The New Way ✨

With App Startup, you can initialize libraries lazily and only when they're actually needed.

Example:

class AnalyticsInitializer : Initializer<Analytics> {
    override fun create(context: Context): Analytics {
        return Analytics.setup(context)
    }

    override fun dependencies(): List<Class<out Initializer<*>>> = emptyList()
}

Then just declare it in AndroidManifest.xml:

<provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    android:exported="false"
    tools:node="merge">
    <!-- This entry makes AnalyticsInitializer discoverable. -->
    <meta-data  android:name="com.example.AnalyticsInitializer"
          android:value="androidx.startup" />
    

And boom — App Startup handles the rest.

Why It's Better ⚡

• Faster launches (no more bloated onCreate()).
• Lazy initialization → only load what's needed.
• Cleaner architecture → each library defines its own setup.

TL;DR

If you want your Android app to launch faster, spend 5 minutes with the App Startup API. It's a small change that makes a big difference.