Qodem Donation Logistics
Streamlined blood donation coordination and bank locator.
- Type
- Personal Project
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 Firebase Cloud Firestore, so the app skips a REST setup and uses Firestore's SDK listeners to keep data live during appointment scheduling.
Firebase integration
- Auth: SMS-based Firebase Auth handles verification — basic traceability with no hardcoded test backdoors.
- Maps: Geographic data from Firestore plots onto the Google Maps API to show nearby clinics, using the user's location for routing.
- QR check-in: A confirmed appointment generates a signed string serialized into a QR code, so the clinic can validate the booking at the door offline, with no 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.