Qodem Donation Logistics
Streamlined blood donation coordination and bank locator.
The Overview
Qodem makes voluntary blood donation easier to coordinate. Users find nearby donation centers from a live clinic map, book a slot, and verify their donation on-site through a generated QR code that doubles as a digital receipt.
The Challenge
Medical scheduling needs reliable backends. Pairing Google Maps location data with realtime database sockets for booking confirmation requires careful networking code that never blocks the main thread.
Session handling was the other tricky piece: signing out has to fully purge cached user data and database instances before a new session begins, otherwise stale records leak across accounts.
Architecture & Technical Decisions
Qodem sits on top of Firebase Cloud Firestore so the app skips the REST setup and relies on Firestore's SDK to keep socket connections alive during appointment scheduling.
Firebase integration
SMS-based Firebase Auth handles user verification, which gives basic traceability without hardcoded test backdoors. Geographic data from Firestore maps onto the Google Maps API to plot nearby clinics, factoring in the user's location for routing. Confirmed appointments generate a signed cryptographic string serialized into a QR code, so the clinic can validate the booking offline at the door without a backend round-trip.
Impact & Results
- SMS-based onboarding that drops the friction for first-time donors.
- Live clinic discovery via Firebase realtime sockets bound to Google Maps.
- Offline appointment verification at the clinic, with no special hardware needed.