Faiz Ullah's 30,000-line React marketplace

Faiz Ullah built a 30,000-line React multi-vendor marketplace with separate authentication systems for customers, sellers, and admins [devto]. Each system has its own protected route guard, such as the ProtectedCustomerRoute component, which checks its own session state independently [devto]. The marketplace features live messaging between buyers and sellers, powered by Firestore's real-time listeners [devto]. Ullah chose Firestore's listeners over a WebSocket server, which simplified the development process. The listeners enable real-time updates, including chat, unread-message counts, and live presence, without manual socket connection management [devto]. Ullah also notes that storing binary media data directly in the database does not scale and recommends offloading it to dedicated media infrastructure immediately [devto]. Additionally, he emphasizes the need for a human checkpoint wherever money leaves the system to prevent fraud attempts [devto].