How DoorDash Interviews in 2026: Process, Questions & What They Score

1. 01

   Find the k nearest restaurants to a given user location (a recurring DoorDash-flavored variant of the k-nearest-neighbors/closest-points problem).

   Tests k-nearest-neighbor selection: a max-heap of size k or quickselect over distances.

2. 02

   Schedule tasks for a single-threaded CPU and return the order in which they are processed.

   Simulation with a priority queue: order tasks by availability then shortest processing time.

3. 03

   Given a grid of rooms, gates, and walls, fill each empty room with the distance to its nearest gate ('Walls and Gates').

   Tests multi-source BFS: flood distances outward from all gates at once.

4. 04

   Find the longest increasing path in a matrix.

   Tests DFS with memoization on a matrix; the DAG insight avoids recomputation.

5. 05

   Compute the maximum path sum between two leaf nodes in a binary tree.

   Tree recursion question: combine left and right leaf paths at each node while tracking a global best.

6. 06

   Given an array, find three elements that sum to a target value (3Sum-style).

   Tests sort plus two-pointer technique and careful duplicate handling.

7. 07

   Implement a Trie (prefix tree) supporting prefix matching.

   Tests trie construction: node maps and terminal flags supporting prefix queries.

8. 08

   Find the largest contiguous subarray sum.

   Kadane's algorithm staple; the O(n) running-maximum recurrence is the expected answer.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   Design a real-time Dasher/driver location-tracking system that ingests high-frequency GPS updates at scale.

   System design: high-frequency GPS ingestion; they probe write throughput, geo-indexing, and staleness trade-offs.

2. 02

   Design DoorDash's food-delivery marketplace/dispatch system from scratch.

   Broad system design: three-sided marketplace flows, ordering, dispatch, and consistency at scale.

3. 03

   Design a matching/dispatch service that assigns Dashers to incoming orders.

   System design: assignment algorithms plus latency, fairness, and retry semantics for dispatch.

4. 04

   Design a notification system for multi-channel order-status updates to consumers, merchants, and Dashers.

   System design: fan-out across channels with ordering, dedup, and delivery guarantees per audience.

5. 05

   Design an ETA-prediction system for deliveries.

   ML-flavored system design: feature pipelines, model serving latency, and fallback estimates.

6. 06

   Design a distributed job scheduler.

   System design: they probe queue partitioning, exactly-once execution, retries, and worker failure recovery.

7. 07

   Design an API rate limiter (often framed as a low-level design exercise).

   Low-level design: token bucket or sliding window behind a clean interface, with concurrency safety.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   Build Dasher payout/pay-calculation logic for a new service that calls an upstream dependency.

   Practical coding: business-rule implementation around an upstream call, with failure and retry handling.

2. 02

   Design and implement an API that aggregates several internal services, handling timeouts and retries.

   Tests service integration: parallel calls with timeouts, retries, and graceful partial failure.

3. 03

   Implement an order or menu module from a given set of business rules.

   Tests translating business rules into clean module design with tests and edge cases.

4. 04

   Given an unfamiliar codebase with a reported bug, use unit tests to isolate and fix the issue, then explain your reasoning as you go.

   Debugging exercise: navigate unfamiliar code, use unit tests to isolate the fault, and narrate reasoning.

5. 05

   In the AI-assisted working session: implement or extend an order-dispatch system, build a 'smart menu composer,' or build a workflow engine that parses a text description and executes steps (e.g., issuing a refund), using an AI coding tool to implement, debug, and validate the change while narrating how you direct and verify its output.

   Tests AI-assisted development: directing a coding tool, then verifying and debugging its output on a real feature.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   How would you improve Dasher retention or reduce Dasher churn?

2. 02

   Design a success-metrics framework for a new DoorDash feature (e.g., group ordering).

3. 03

   How would you evaluate and prioritize DoorDash's expansion into a new market or vertical?

4. 04

   A key marketplace metric (e.g., order completion rate) drops 10% week-over-week. How would you investigate the cause?

5. 05

   How would you balance trade-offs across consumers, Dashers, and merchants when changing delivery pricing or Dasher pay?

6. 06

   Estimate the addressable market for DoorDash entering a new city or country.

1. 01

   Write a SQL query to compute peak-hour earnings or delivery-latency percentiles from a given schema (expect window functions, CTEs, and multi-table joins).

   SQL depth: window functions, CTEs, and multi-table joins over a delivery-data schema.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   Tell me about your biggest failure and what you learned from it.

2. 02

   Describe a time you disagreed with a teammate or manager and how you resolved it.

3. 03

   Tell me about a decision you made with incomplete data.

4. 04

   Walk me through a project where priorities or requirements shifted midway through.

5. 05

   Tell me about a time you took ownership of a problem outside your defined scope ('be an owner').

6. 06

   Describe a time you had to act with urgency and imperfect information ('bias for action').

7. 07

   Tell me about a time you helped make your team more inclusive or collaborative ('make room at the table').

8. 08

   Why DoorDash? What do you like or dislike about the product as a consumer, merchant, or Dasher?