For field technicians, clinicians and drivers, connectivity is a luxury, not a guarantee. An app that only works online simply doesn't work. Here's how we build offline-first React Native apps that feel instant and never lose a user's work.
Offline-first is a mindset, not a feature
The core shift: treat the local device as the source of truth for the user's session, and the server as something you sync toward when a connection is available. Every action should succeed immediately against local storage, then reconcile in the background.
The building blocks
- A local database (e.g. SQLite/WatermelonDB) that the UI reads and writes directly.
- A durable outbound queue of changes waiting to sync, persisted, so a crash or restart loses nothing.
- Background sync that drains the queue whenever connectivity returns.
The user should never see a spinner waiting on the network to do their job. They act; the app syncs when it can.
Conflict resolution: decide the rules up front
When two devices edit the same record offline, someone has to win. There's no universal answer, it's a product decision:
- Last-write-wins for simple, low-stakes fields.
- Field-level merges when edits touch different attributes.
- Explicit review for high-stakes conflicts where guessing is dangerous (e.g. clinical data).
UX patterns that build trust
Offline apps live or die on how clearly they communicate state. Show sync status honestly, mark records as "pending", confirm when everything's saved to the server, and never silently drop a change. Trust is the whole product.
Build it with us
Tanco Tech builds native and cross-platform apps designed for the real world, offline-first, secure and fast. See our mobile services or scope your app.
