I'm building a consumer app and want channel fallback when push fails

For a consumer app, channel fallback usually means: if a higher-priority channel like push fails or isn’t available, you automatically try another channel such as email, SMS, or in-app.

A practical fallback strategy:

1. Try push first

   • Best for real-time, low-cost delivery.
   • If the device token is invalid, user opted out, or push provider returns a hard failure, treat it as unavailable.

2. Use immediate fallback rules

   • Retry push for transient failures only:
     • timeouts
     • rate limits
     • 5xx errors
   • If it still fails, fall back to the next channel.

3. Define fallback priorities Example:

   • Push
   • In-app notification
   • Email
   • SMS
     The order depends on urgency and user preferences.

4. Respect user preferences and consent

   • Let users opt into channels.
   • Don’t send SMS if they haven’t consented.
   • Consider quiet hours for SMS/email.

5. Use message-specific policies

   • Critical alerts: push → SMS → email
   • Promotional: push → in-app → email
   • Transactional: push → email, maybe no SMS unless important

6. Deduplicate notifications

   • If push eventually succeeds after fallback already sent email, avoid double alerting unless the message is meant to be multi-channel.

7. Track delivery outcomes

   • Log:
     • sent
     • delivered
     • failed
     • retried
     • fallback used
   • This helps tune fallback rules.

8. Implement a channel state model Example states:

   • available
   • temporarily_failed
   • hard_failed
   • opted_out

9. Make fallback asynchronous

   • Don’t block the user-facing flow on delivery attempts.
   • Queue the notification orchestration in the background.

If you want, I can also help you with:

• a fallback decision tree
• a data model for channel preferences and failures
• or sample code for implementing this in your backend.