Helper Sync – a sync platform for apps that work offline
Our platform for apps: all data is kept on the device, the app works offline, and changes reach other devices in real time.
It runs at sync.helper.lt, and our own apps use it.
- Project
- Own product
- Our role
- The whole solution
- Years
- 2025–2026
- Technologies
- Rust, PostgreSQL, Flutter / Dart, SQLite, Server-Sent Events
The task
Apps that have to work offline need one reliable way to keep their data on the device and sync it with the server and other devices – without building it anew for every app.
The solution
A sync platform: apps keep all their data on the device, in SQLite, and work offline, while the server collects the changes and passes them on to other devices.
- Changes upload in batches and download incrementally.
- Server-Sent Events push changes to other devices in real time.
- Conflicts are resolved on the server, row by row.
- Deleted rows are archived, never lost.
- Access rules per table and row filters decide who sees what.
- A code generator builds the client's database migrations from the server schema.
- One server serves many apps.
- Our Flutter sync engine runs in the apps.
Back online, changes go up in batches
Only new data comes down
Helper Sync
Conflicts resolved on the server
Row by row
Deleted rows archived
Nothing is lost
Access rules
Per table, with row filters
Server-Sent Events: changes in real time
Results
- The platform runs at sync.helper.lt.
- Our own apps use it.
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