Design DoorDash
PremiumProduct architectureHard
- Food delivery
- Courier dispatch
- Order state machine
Quick answer
This product architecture interview question asks you to design DoorDash. Aim for a design that meets its requirements at the stated scale, then explain its main components, data flow and trade-offs. Interviewers want to see how you scope the problem, size it and defend each choice.
The problem
Design DoorDash, a food delivery marketplace where customers order from nearby restaurants, restaurants cook the food and couriers called Dashers deliver it. The hard parts are coordinating three apps on one order, sending Dashers so they arrive when the food is ready, and keeping menus, payments and tracking correct at the dinner peak.
What must the system do?
- Browse and order: Customers see open restaurants that deliver to them, with fees, ETAs and menus showing sold-out items, then pay for a cart from one restaurant.
- Dispatch: A nearby Dasher is offered the delivery so they reach the restaurant about when the food is ready; a Dasher may carry 2 orders at once.
How well must it do it?
- Exactly-once orders: A retried Place Order creates one order, one authorization and one ticket at the restaurant.
- Single assignment: An order has at most one active Dasher, and no Dasher holds more than 2 orders.
What scale should you design for?
Use these numbers in your estimates.
The scale numbers unlock with this questionUnlock
Key concepts
- Food delivery
- Courier dispatch
- Order state machine
- Geospatial index
- Live tracking
- Idempotent payments
How you’ll practise
- Requirements
- Core entities
- API design
- Client and server flow
- Scale and edge cases
- 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 product architecture design round.
- Clarifies the requirements before drawing anything
- Uses a few numbers that actually change the design
- Draws a clear path from the client to storage
- Picks storage and caching with reasons, not by habit
- Explains what breaks first under load and how to fix it
- States trade-offs openly instead of claiming a perfect design
Questions people ask about this interview question
- Which design type is this question?
- It is a product architecture question. You design DoorDash and explain your choices the way you would in an interview.
- Is this question asked at entry level?
- It is marked Hard. It suits engineers preparing for senior interviews, where you are expected to drive the discussion and go deep on trade-offs.
- What should I cover first?
- Start with the requirements: what the system must do, how well it must do it and which numbers change the design. 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