Messaging Sync: Scaling Mobile Messaging at Airbnb
Article Summary
Zhiyao Wang and the Airbnb team tackled a massive problem: their mobile inbox was loading like a 2001 webmail client. With 100k+ messages per hour, every tap meant a network request, killing UX on slow connections.
Airbnb's Hosts and Homes team rebuilt their mobile messaging architecture from the ground up with Messaging Sync. The old system fetched data on every screen change, creating slow loads, data inconsistencies, and zero offline capability for their most-used feature.
Key Takeaways
- Cut API latency in half with delta syncing instead of full fetches
- Enabled offline message reading by storing locally with sequence IDs
- Increased mobile messages sent by 3.8% (Android) and 5.3% (iOS)
- Reduced response payload size dramatically through incremental updates
- Built dual-API validation to catch regressions during migration
Critical Insight
By switching from fetch-on-every-tap to delta syncing with local storage, Airbnb doubled inbox speed and drove daily visits up 200% on Android and 96% on iOS.
