E-Commerce App

Full-stack shopping app backed by Firebase. Built and shipped by devShakib.

A fully functional e-commerce application with product listings, cart management, user authentication, and real-time order tracking — powered by Firebase Authentication, Firestore, and Storage.

The cart is where an e-commerce app gets difficult, because it lives in two places at once. A cart held only on the device disappears when the user switches phones; a cart held only on the server fights with offline use — so it has to merge, and merging means deciding what happens when the same item was added on both sides.

Inventory is the second problem. Stock counts change between the moment a product is listed and the moment payment completes, so the check that matters is at checkout rather than at browse time, and it needs to be a transaction rather than a read followed by a write.