Rashid Shamloo

• User authentication using Firebase Auth and Firebase UI (with anonymous user setup and handling merge conflicts) • Data storage (todo list and theme preference) using Firestore • Real-time data with latency compensation and reduced number of database queries by grouping multiple queries • Database security rules to limit access of a user only to his/her own data • Todo list drag and drop reordering and animations using Framer Motion

• Custom back-end using TypeScript/Node.js/Express.js that fetches data from multiple public geo IP APIs • Back-end security using CORS, rate limiting per IP, and private key • Custom Express.js middlewares to verify the private key, apply rate limiting, and add custom fields to the JSON response • Front-end in React.js/Tailwind/Leaflet.js with error handling and data re-fetch on failure • Made custom NPM packages for applying timeout and multiple abort signals to fetch requests: t.ly/ZcDA