Designed and built a consent-first GPS tracking ecosystem featuring a React Native mobile app, a Node.js backend, and a real-time web dashboard. Implemented robust background location services with a permanent Android notification bar to comply with privacy laws. Integrated an offline queue using AsyncStorage that buffers up to 2,000 coordinates during connection drops and auto-syncs via batch uploads once restored. Fingerprinted devices with stable hardware-linked IDs and displayed active paths and accuracy zones on a dark-themed Leaflet.js dashboard map.