PharmaFinder: Geospatial Search for 3,000+ On-Duty Pharmacies in Greece

The Motivation Behind the Project

Finding an open overnight pharmacy in Greece during emergencies shouldn't require deciphering fragmented municipal PDF rotas. PharmaFinder delivers instant geospatial search with offline-first caching.

Core Features and Design Goals

• Instant GPS proximity ranking across thousands of verified pharmacies
• MapLibre GL vector basemaps with OpenFreeMap and MapTiler dual-layer failover
• Offline-cached emergency duty rotas with automated daily updates
• 1-tap directions launch to Google Maps and direct phone dialer integration

Technical Implementation

• Engineered Haversine distance calculations directly in memory for instant list sorting
• Combined MapLibre GL in WebView with native touch bridges for 60fps pin panning

The Technology Stack

Built with Expo SDK 57, React Native, MapLibre GL, and TanStack React Query.

Final Reflections

Vector basemaps with open tile fallback guarantee zero API rate-limit dropouts during critical emergencies.