DoorDash Coding & Algorithms Interview Questions
DoorDash Coding & Algorithms interview questions typically emphasize practical problem solving under time pressure, clear code, and product-minded tradeoffs. What’s distinctive is a bias toward realistic engineering tasks—scheduling, graph traversal, and array/string manipulation appear often—combined with an expectation that you communicate tradeoffs, test edge cases, and iterate quickly. Interviewers assess algorithmic thinking, correctness, complexity reasoning, and the ability to refactor or extend solutions when given follow-ups. Expect an initial technical screen followed by a loop of 2–4 interviews that blend live coding with behavioral and sometimes system-design conversations. For interview preparation, prioritize consistent timed practice on medium-to-hard problems, rehearse speaking your thought process, and run mock interviews in your target language and editor. Refresh core data structures, common patterns (DFS/BFS, two pointers, heaps, hash maps, dynamic programming), and time/space analysis. Finish prep by practicing end-to-end: state assumptions, outline an approach, code defensively, and validate with tests so you can both solve and clearly explain your solutions during the loop.

"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"

"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"

"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."

"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."

"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."
Can two names match with ≤2 swaps?
You are given two restaurant names represented as strings s and t of equal length (same character set, case-sensitive). In one operation, you may swap...
Calculate Courier Earnings
Design a function to calculate total courier pay from a set of delivery orders. Assume time is represented as integer minutes, and intervals are half-...
Compute courier pay and implement load balancing
Problem 1: Compute courier (delivery driver) pay You are given a sequence of delivery-related events for a courier during a day. Your task is to compu...
Find longest common ordered restaurant list
You have two delivery drivers who each have a pickup plan represented as a list of restaurant IDs (strings). Because there is only one car, the combin...
Implement minimum window substring with counts
Implement min_window_with_counts(s, t) Task Write a function: - min_window_with_counts(s: str, t: str) -> tuple[int, int] that returns the inclusive (...
Design dasher-to-order assignment algorithm
You are building a real-time 'dasher picker' that assigns delivery drivers (Dashers) to incoming orders. Define objective(s) (e.g., minimize ETA and c...
Compute delivery times on a grid
You are given a 2D grid with cells marked as 'M' (warehouses), 'C' (customers), 'X' (obstacles), and '.' (roads). You can move up, down, left, or righ...
Implement round-robin load balancer
Implement a load balancer that distributes incoming requests across N backend servers in strict round-robin order. Requirements: ( 1) Support addServe...
Find minimum processing rate
Find minimum processing rate You are given an array piles where piles[i] is the number of items in the i-th pile and an integer H (total hours). Find ...
Generate the next lexicographic array arrangement
Generate the next lexicographic array arrangement Given an integer array nums (which may include negative numbers and duplicates), modify nums in plac...
Compute nearest courier for each customer
Compute nearest courier for each customer You are given two sets of 2D points: customers C = {c1..cn} and active couriers (dashers) D = {d1..dm}. Each...
Compute earliest arrival in time-grid
Question LeetCode 778. Swim in Rising Water – Given an n x n integer grid where grid[i][j] is the earliest time you can enter the cell, starting from ...
Solve string match and DashMart BFS
Question Implement a string-matching function that returns the first index of a pattern in a text (akin to LeetCode 28 Implement strStr()). 2) “Dash M...
Implement string matching with follow-up
Question Given a text T and a pattern P, implement a function firstIndex(T, P) that returns the starting index of the first occurrence of P in T, or -...
Count changed nodes in N-ary trees
Question Given two N-ary trees (old and new versions) where each node has a key (string), value (int), and list of children, compute how many nodes ar...
Find names similar by one swap
Question LeetCode 859. Buddy Strings – Given a target string and a list of strings, return all list entries that can match the target by swapping at m...
Implement string-path file system operations
Question LeetCode 1166. Design File System – extended to support Create(path, value), Get(path), Set(path, value) and Delete(path) with validation rul...
Determine equality after limited swaps
Question LeetCode 1790. Check if One String Swap Can Make Strings Equal Follow-up: Given two strings, determine if they can become anagrams of each ot...
Design a hierarchical path registry
Design a hierarchical path registry Implement an in-memory hierarchical path registry. Support: create(path, value) to create a new path with an integ...
Find max distance between alive tree nodes
Find max distance between alive tree nodes Given a binary tree, define alive nodes. Base case: alive nodes are the leaves. Find the maximum distance (...