Design a food delivery app (low-level design)
PremiumLow-level designMedium
- State machine
- Order lifecycle
- Strategy pattern
Quick answer
This low-level design interview question asks you to design a food delivery app (low-level design). Aim for a design that is modelled as clear classes, interfaces and relationships that can handle new requirements without a rewrite. Interviewers want to see how you name responsibilities, keep classes small and reason about change.
The problem
Food delivery app low level design, in the style of Swiggy or Zomato: build the object model for restaurants, menus, a cart, pricing, orders and delivery partners. The hard parts are an order status state machine with no illegal jumps, prices frozen at checkout, and assigning a nearby partner.
A customer browses restaurants, builds a cart from one restaurant's menu with item customisations, applies a coupon, pays and places the order. The restaurant accepts and prepares it, a delivery partner is assigned, picks it up and delivers it. The customer sees each status change, can cancel within rules, and rates the order.
What must a food delivery app (low-level design) do?
- Order: Placing an order freezes the cart into line items with prices. Status moves through PLACED, ACCEPTED, PREPARING, READY, PICKED_UP, DELIVERED, or CANCELLED and REJECTED.
- Assignment: When the restaurant accepts, assign a nearby available delivery partner; if none accepts within 2 minutes, widen the radius.
How well must it do it?
- Correct transitions: No illegal status jump (for example DELIVERED after CANCELLED); every transition is recorded with time and actor.
- Consistent pricing: The price shown in the cart is the price charged; a later menu change does not alter a placed order.
What scale should you design for?
Use these numbers in your estimates.
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Key concepts
- State machine
- Order lifecycle
- Strategy pattern
- Observer pattern
- Dispatch assignment
- Cart and checkout
How you’ll practise
- Requirements
- Core objects
- Class relationships
- Key flows
- Extensibility
- Wrap-up
Lala, personalized to you, gives a hint when you ask and reviews your design when you are ready.
What do interviewers look for?
In any low-level design round.
- Lists the use cases before writing classes
- Gives each class one clear responsibility
- Uses interfaces where behaviour is likely to change
- Applies a design pattern only when it solves a real problem
- Handles edge cases and invalid states explicitly
- Walks through one use case end to end with the model
Questions people ask about this interview question
- Which design type is this question?
- It is a low-level design question. You design a food delivery app (low-level design) and explain your choices the way you would in an interview.
- Is this question asked at entry level?
- It is marked Medium. Entry-level engineers can practise it, but it expects you to reason about requirements and trade-offs, not only list components.
- What should I cover first?
- Start with the use cases and the core entities, then the responsibilities of each one. Agree on scope with the interviewer before you design anything.
- Can I practise it for free?
- It is a premium question. Sign up and unlock it once for 10 credits; it then stays unlocked. When you finish, Lala, your personalized AI mentor, can review your design for 30 credits.
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Updated · Written by the SevyDevy team