Critical bug in production. Users are crashing.

Option 1: Submit to App Store, wait 2-7 days for review.
Option 2: Push OTA update, fixed in 15 minutes.

We chose Option 2.

What Are OTA Updates?

Over-the-air updates let you update JavaScript code without app store approval.

What you CAN update:

• Bug fixes
• UI changes
• API endpoint changes
• Feature flags

What you CANNOT update:

• Native code (Swift/Kotlin)
• App permissions
• Binary changes

Expo Updates

# Deploy update to all users
expo publish

# Or target specific release channel
expo publish --release-channel production-v1

Users get updates:

• On next app launch
• In background (silently)

CodePush (Microsoft)

import codePush from "react-native-code-push";

const App = () => {
  // Check for updates on app start
  codePush.sync({
    updateDialog: true,
    installMode: codePush.InstallMode.IMMEDIATE
  });
  
  return <MainApp />;
};

export default codePush(App);

Real-World Use Case

Kallie Snake bug: Score not saving after game over.

Fix deployed:

1. Push code fix to GitHub (5 min)
2. CI/CD builds OTA bundle (3 min)
3. CodePush distributes to users (instant)
4. 95% of users updated within 24 hours

Total time: 8 minutes (vs 3-7 days for app store)

Rollout Strategies

1. Staged Rollout

// 10% of users first
codePush.sync({ deploymentKey: "10-percent" });

// If no crashes after 24h, roll out to 100%
codePush.sync({ deploymentKey: "production" });

2. A/B Testing

const userId = getUserId();
const variant = userId % 2 === 0 ? "A" : "B";

codePush.sync({ deploymentKey: variant });

Cost

Expo Updates: Free
CodePush: Free (up to 500 MAU), then $0.01/user/month

Limitations

• Can't update native modules
• Users must be online to receive updates
• Apple requires "small changes only" (no major features)

Want instant updates for your app?
Deploy with OTA