eMushrif

Every bus carries a GPS unit publishing its location every 5–10 seconds via MQTT — a protocol designed for constrained hardware, with as little as 2 bytes of overhead per message. The Node.js backend subscribes to the broker, runs geofence checks on each event, and pushes the result over WebSocket only to parents tracking that specific bus. No polling. No broadcast floods. The entire pipeline — device to parent screen — completes in under 2 seconds.

Every document in MongoDB is scoped to a schoolId at the root level. Isolation is enforced at the API middleware layer — not in individual controllers — so no query can reach another school's students, routes, or trip history. When eMushrif expanded from Oman to Kuwait, it required zero architectural changes: separate MongoDB instances per country, with the API routing requests from each school's country field.

The parent app started in React Native and was migrated to Flutter — delivering a single codebase across iOS and Android without sacrificing performance for live map rendering or background push alerts. Arabic RTL was a first-class layout direction from the start, not retrofitted: Flutter's bidirectional text and Directionality widget handle RTL natively, with bilingual Arabic/English strings synced to the backend content model. The result: a product that feels at home in its market.