DoorDash Interview Questions
Practice 254 real interview questions from DoorDash. Covers Analytics & Experimentation, Coding & Algorithms, System Design, Behavioral & Leadership. For roles including Software Engineer, Data Scientist, Machine Learning Engineer, Analytics Engineer.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
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"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
How would you mentor as a senior?
Behavioral Question (Senior IC): Mentoring You are interviewing for a senior data role. The interviewer asks: > As a senior, how would you mentor othe...
Diagnose completed orders drop in Los Angeles
You are a data scientist at DoorDash supporting the consumer pricing team. The number of completed delivery orders in Los Angeles has dropped meaningf...
Debug round-robin request router
Round-Robin Request Router with Health and Dynamic Membership You are given a list of backend servers and an incoming stream of requests. Implement a ...
Design a 3-day online donation system
System Design: 3-day donation campaign Design an online donation system for a 3-day fundraising campaign. Requirements - Users can donate money to a c...
Walk Through an ML Project
Prepare a deep dive on one machine learning project you have worked on. In a 60-minute interview, explain: - the problem statement and why it mattered...
Design a Low-Latency Store Recommender
You are designing the home-page store recommendation system for a food delivery app such as DoorDash. A request contains very little context: primaril...
Answer feedback, conflict, and failure questions
Behavioral Questions Prepare structured answers (use STAR: Situation, Task, Action, Result) for: 1. Giving constructive feedback: Tell me about a time...
Compute cart total with best promotion
Assume you are implementing a checkout price calculator for an online shopping cart. You are given: - A list of items in the cart. Each item has: - ...
Investigate Falling Successful Orders in LA
DoorDash observes that the number of successful orders per day in the Los Angeles market has declined materially over the last 2 weeks relative to the...
Design a resilient dasher payment system
System Design: End-to-End Payouts from Order Lifecycle Events You are designing a system that computes delivery driver (Dasher) payouts from an event ...
Debug a driver assignment bug
Given a service that selects the best delivery driver ("dasher") for an order, users report incorrect assignments. With a provided codebase and failin...
Experiment on increasing order notifications
Experiment Design: Increasing Order‑Related Push Notifications Context You are asked to design, measure, and make decisions about increasing order‑rel...
How would you test a bike delivery option?
Case: Launch a bike-delivery option You work on a food delivery marketplace (customers place orders; couriers deliver). The team is considering launch...
Write SQL for monthly spend and ratios
Assume you are working with a food delivery dataset. Tables (schemas) users - user_id INT PRIMARY KEY - annual_income_usd INT - signup_ts TIMESTAMP re...
Design a notification system
System Design: Multi-Channel Notification Platform Context Design a multi-tenant notification platform that delivers messages across email, SMS, and m...
Implement a consistent hashing ring
Implement a class ConsistentHashRing that distributes keys across servers using a hash ring with virtual nodes. Required API: - ConsistentHashRing(rep...
Design review system with voting and rewards
Design: Scalable Product Reviews with Voting and Rewards Context You are designing a reviews feature for a large e-commerce marketplace. Customers can...
Find Each Cell's Nearest Source
Given an m x n grid containing 1 for source cells and 0 for regular cells, compute for every cell the shortest 4-directional distance to any source ce...
Design dynamic connectivity with alive nodes
Design a data structure to maintain an undirected graph of N nodes, where each node has a boolean 'alive' flag. Support the following operations effic...
Debug a cache incident end-to-end
Incident Scenario: Elevated Latency and Surge in Cache Misses You are paged for elevated tail latency and a spike in cache misses in a microservice th...