18 % faster deliveries
Courier app with offline mode
- Client
- ExpressLine
- Industry
- Logistics
- Year
- 2022
- Type
- Mobile app
- Duration
- 5 months
- Team
- 4 people
01 — The problem
220 couriers worked from paper route sheets. Deliveries were ticked off on the sheet and keyed into the system by hand in the evening. Dispatchers did not know where couriers were, customers did not know when to expect them, and when the records disagreed there was no way to investigate — the paper was gone.
02 — What we built
Offline was the whole project
Couriers work in basements, lifts and industrial estates with no signal. We chose an architecture where the app always writes to a local SQLite database and syncs in the background when connectivity returns. The courier never notices whether there is internet — that mattered more than any feature.
Resolving sync conflicts
The hardest part. If a dispatcher reassigned a job while the courier was offline and had already marked it delivered, something has to win. We settled on a rule: a delivery confirmed by the courier always wins, the reassignment is rolled back, and the dispatcher gets a notification.
Photo and signature as proof
The courier photographs the handover point or captures a finger signature. The image is compressed on device and uploads on first connection. Disputed "never delivered" claims dropped by 70 %.
Daily route planning
Each morning the courier gets a sorted stop list with a route on the map. The ordering is computed server-side with delivery windows taken into account.
03 — Result
- −18 %
- average delivery time
- 220
- couriers moved off paper
- −70 %
- disputed deliveries
- 0
- data loss while working offline