The delivery app must provide a seamless end-to-end experience for customers, couriers, and administrators by enabling users to browse available vendors, place orders with secure payment options, and track deliveries in real time from confirmation to drop-off couriers should receive optimized routing, status updates, and the ability to accept or decline jobs, while vendors must be able to manage menus or inventories, view incoming orders, and update preparation times; the system should include user authentication, profile management, push notifications, and location services, all supported by a scalable backend capable of handling high-volume transactions with low latency; administrators need access to dashboards for monitoring system performance, managing users and vendors, resolving disputes, and reviewing analytics; the app must maintain strong data privacy and security practices, offer multilingual and accessibility-friendly interfaces, and be designed for both iOS and Android with a responsive, intuitive UI that supports future feature expansion.