After months of building, I just released Zesto — a production-ready, multi-city food delivery platform inspired by Zomato and Swiggy. It consists of 4 Flutter apps backed by a Firebase backend with 23 Cloud Functions. In this article I'll walk through the key architecture decisions I made along the way. What I Built Customer App — OTP login, restaurant discovery, cart, Razorpay payments, live driver tracking Driver App — automatic job assignment, step-by-step delivery slider, background GPS Restaurant App — live order dashboard, menu management, earnings Admin Panel — Flutter Web, multi-city, restaurant and driver management Demo: https://youtube.com/shorts/rL2M5O5Tk50 Architecture Overview All 4 apps share a single Firebase project. Each app is independent with its own package name and Firebase registration, but they all read and write to the same Firestore collections.…