Replace Amplitude: faster cold start

Q: How do I measure cold start before / after?

iOS: Xcode Organizer's Launch Time metric (aggregate from real users) or Instruments → App Launch template (synthetic). Android: `adb shell am start -W /. ` or Play Console's Vitals → Startup time. Measure before removing the old SDK, after, and compare on the same device class.

Q: Does Respectlytics block the main thread on init?

No. `Respectlytics.configure(appKey:)` is synchronous but does only in-memory work (allocates the ring buffer). The network flush runs on a background dispatch queue / coroutine.

▸Example Amplitude call (the "before")

js Respectlytics

import { Amplitude } from '@amplitude/analytics-react-native';

await Amplitude.init('YOUR_API_KEY', userId, {
  trackingOptions: { ipAddress: true, language: true, platform: true },
});

await Amplitude.identify({
  email: email,
  plan: 'pro',
});

await Amplitude.track('Paywall Purchase', { value: price, currency: 'USD' });

Heavy analytics SDKs do work at app launch — reading identifiers, initialising queues, network dispatch — that compounds visibly on lower-end devices. Respectlytics's SDK adds typically under 30ms to cold start, vs 100-300ms for Firebase Analytics's full initialisation chain.

☑Remove Amplitude cleanly

1
Remove the Amplitude SDK from your build (CocoaPods / SPM / Gradle / npm / pub)
2
Remove Amplitude.initialize(...) and track(...) call sites — replace with Respectlytics.configure() and Respectlytics.track("event_name")
3
Audit for Identify operation usage — those set per-user properties; remove them
4
If you used Amplitude Experiment for feature flags, plan a separate migration (e.g., GrowthBook or LaunchDarkly) — Respectlytics is analytics, not flagging
5
Confirm IDFA / AAID surfaces in your Info.plist + AndroidManifest are no longer needed by other SDKs before removing them

⇋Amplitude vs Respectlytics — faster cold start

	Amplitude	Respectlytics
Typical cold-start contribution (p50)	— see tool note above	< 30ms
Initialisation work on launch	Reads IDFA/AAID, opens SQLite, spins up threads	Allocates ring buffer (RAM-only)
Number of background threads spawned	— typically 2-4	1
Synchronous I/O on init	— typical (SQLite open)	None

❓Frequently asked questions

How do I measure cold start before / after?

iOS: Xcode Organizer's Launch Time metric (aggregate from real users) or Instruments → App Launch template (synthetic). Android: adb shell am start -W <package>/.<activity> or Play Console's Vitals → Startup time. Measure before removing the old SDK, after, and compare on the same device class.

Does Respectlytics block the main thread on init?

No. Respectlytics.configure(appKey:) is synchronous but does only in-memory work (allocates the ring buffer). The network flush runs on a background dispatch queue / coroutine.

What's typical magnitude of improvement?

On a mid-range Android device, removing Firebase Analytics + AppsFlyer typically saves 100-300ms off cold start, depending on Google Play Services init state. On iOS the delta is usually 50-150ms. Effect is more pronounced on cold-start (uncached) than warm-start launches.

Does cold-start improvement actually affect business metrics?

Yes — first-session abandonment correlates with launch latency in published benchmarks. A 100ms improvement on the slowest deciles of your device distribution can show a measurable first-day retention lift.

⇢Related migration guides

Replace Amplitude to speed up cold start