Sumarivu, an offline-first news app

In-house build. Our own product, not client work.

Label: IN-HOUSE BUILD
Result: ~65% fewer errors after the rebuild
Stack: Flutter · FastAPI · Supabase · Drift (SQLite)

Problem

Slow cold starts and error-prone code as features grew.

Approach

A Clean Architecture migration of both the backend and the Flutter app.
On-demand ingestion, parallel profile sync and composite database indexes.
Offline-first reading history with bulk sync, backoff and conflict resolution.

Architecture

- Flutter app Clean Architecture · feature modules
- Drift (SQLite) Offline history on the device
- Sync engine Bulk sync · backoff · conflict resolution
- FastAPI On-demand ingestion · parallel profile sync
- Supabase PostgreSQL · composite indexes

The app reads from its own local database first and syncs in the background, so it works on a train with no signal. The sync layer is drawn in red.

Result

About 65% fewer errors. The 4.5s cold starts were diagnosed and addressed.