Food Delivery (Swiggy/Zomato)

Design a food delivery platform like Swiggy or Zomato: customers browse restaurants, build a cart, place orders, restaurants accept and prepare them, and delivery agents pick up and deliver. It's a three-sided marketplace, so the design has to coordinate three actors around one order lifecycle.

Requirements

Functional

• Customers search restaurants by location, cuisine, rating; view menus with item availability.
• Cart holds items from one restaurant at a time; apply coupons; see bill (items, taxes, delivery fee, packaging).
• Place order and pay (online or cash on delivery).
• Restaurant accepts or rejects; marks food preparing and ready.
• System assigns a nearby delivery agent; agent picks up and delivers.
• Live order tracking with status updates and agent location.
• Cancel before the restaurant starts preparing (full refund); later cancellations follow policy.
• Ratings for restaurant and agent.

Non-functional

• An agent carries at most N orders at a time (often 1, or batched 2 from the same restaurant).
• Status updates reach the customer within seconds.
• Assignment and pricing logic swappable per city.
• Idempotent order placement and payment callbacks.