Slow app startup

Issue summary

Startup performance issues occur when the app takes too long to initialize, delaying the appearance of the first usable screen. This is often caused by heavy operations or blocking tasks running on the main thread during startup.

Platform target and tolerance:

• Target: 2.5 seconds
• Tolerance: up to 5 seconds

Why it matters

Slow startup times frustrate users, increase abandonment, and negatively affect ratings and retention. Optimizing startup boosts user satisfaction and improves the perceived quality of the app.

How severity is calculated

The platform calculates a severity score for startup issues based on how much the measured startup time exceeds the defined target and tolerance.

Severity	Definition
No issue raised	Startup time is below target (≤ 2.5 sec). No significant issue.
Low–Medium	Startup time exceeds target but is within tolerance (2.5–5 sec). Gradual impact based on distance from midpoint.
High–Critical	Startup time exceeds tolerance (> 5 sec). Score capped at 100, indicating maximum severity.

How to fix a slow app startup issue

Since the Kotzilla platform has detected a startup performance problem, your focus should now be on investigating what’s happening during your app’s initialization, particularly within the onCreate method of your Application class during and immediately after Koin is initialized.

Focus on:

• Deferring or breaking up what happens at app launch
• Reducing how much must be ready before the first screen shows
• Using lazy modules, inject(), and graph optimization to improve first-load performance

Recommended actions

1. Lazy Initialization
   Koin creates singletons lazily by default, meaning instances are created only when first needed. Avoid forcing eager initialization accidentally through createdAtStart() or premature get() calls.

   To further improve startup performance, consider using inject() inside your classes to lazily obtain dependencies. This defers their creation until actually accessed, which is especially helpful for non-essential services like analytics or remote config.

2. Lazy modules for deferring heavy initialization
   Use Koin’s lazy modules feature to defer loading entire sets of dependencies until required. Combine this with background thread execution (i.e., coroutines on Dispatchers.Default) to keep startup smooth.

3. Optimize the dependency graph
   Even with lazy initialization, a complex or tightly coupled dependency graph can cause transitive eager loads.

   • Break down large dependencies into smaller parts
   • Reduce unnecessary coupling between modules
   • Isolate heavy or optional dependencies for lazy or asynchronous loading

   This ensures only essential components are initialized at startup.

Use the Kotzilla SDK API and the Console to investigate

You can use the Kotzilla SDK API to add custom logs, trace execution time, and capture additional context during your app’s startup. This helps pinpoint heavy operations, measure performance of specific code blocks, and gather detailed diagnostics.

The information you log will appear in the user sessions Timeline view of the Kotzilla Console, providing a clear, chronological view of events to help troubleshooting.

Initialize the SDK in your startKoin block and instrument critical startup code for deeper insights. For full usage details, see the Kotzilla SDK API documentation.

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