TL;DR — GPS Fleet Tracking

Design a GPS fleet tracking system that monitors the real-time location of 500K vehicles, supports geofencing with entry/exit alerts, optimizes delivery routes, and provides historical trip replay. Each vehicle reports its GPS position every 5 seconds, and the system must process these updates to provide a live fleet map, detect geofence violations within 10 seconds, and enable dispatchers to track any vehicle's current position and route progress. Key features: Real-time vehicle position tracking on a live map. Geofencing: create polygon/circle zones with entry/exit alerts.