DoorDash vs MongoDB Interview Questions
DoorDash lists 78 LeetCode interview questions while MongoDB lists 24. They share 6 problems — 8% of DoorDash's bank and 25% of MongoDB's. Focus on the overlap first, then drill into 72 DoorDash-only and 18 MongoDB-only questions.
Overview
Preparation Strategy
Step 1 — Shared core: Solve the 6 overlapping problems first. These are the highest-yield questions for candidates interviewing at both DoorDash and MongoDB.
Step 2 — Company-specific depth: Add DoorDash-specific problems like Walls and Gates, Longest Increasing Path in a Matrix, Binary Tree Maximum Path Sum and MongoDB-specific problems from the exclusive lists below.
Step 3 — Difficulty tuning: DoorDash skews harder in our data. Budget extra time for Hard problems if you are targeting that company.
Difficulty Comparison
Top Shared Topics
6 Shared Questions
High-priority problems to practice for both DoorDash and MongoDB.
| Problem | Difficulty |
|---|---|
| Implement Trie (Prefix Tree) | Medium |
| Course Schedule II | Medium |
| Sliding Window Maximum | Hard |
| LRU Cache | Medium |
| Merge k Sorted Lists | Hard |
| Merge Intervals | Medium |
Unique to DoorDash (72)
Problems in DoorDash's list that do not appear at MongoDB.
Unique to MongoDB (18)
Problems in MongoDB's list that do not appear at DoorDash.
| Problem | Difficulty |
|---|---|
| Word Break | Medium |
| Snapshot Array | Medium |
| Intersection of Two Arrays | Easy |
| Text Justification | Hard |
| Convert JSON String to Object | Hard |
| Insert Interval | Medium |
| Web Crawler Multithreaded | Medium |
| Stock Price Fluctuation | Medium |
| Merge Two Binary Trees | Easy |
| Lowest Common Ancestor of a Binary Tree | Medium |
| Design Search Autocomplete System | Hard |
| Lowest Common Ancestor of a Binary Tree III | Medium |
Frequently Asked Questions
How many LeetCode questions do DoorDash and MongoDB share?
DoorDash and MongoDB share 6 LeetCode interview questions. 72 problems appear only in DoorDash's list and 18 appear only in MongoDB's list.
What topics overlap most between DoorDash and MongoDB?
The most common shared topics between DoorDash and MongoDB are Hash Table (2 shared questions), Design (2 shared questions), Array (2 shared questions), Heap (Priority Queue) (2 shared questions), Linked List (2 shared questions). Mastering these areas prepares you for both companies.
Which company asks harder LeetCode questions: DoorDash or MongoDB?
DoorDash has 7 Easy, 45 Medium, and 26 Hard questions. MongoDB has 3 Easy, 15 Medium, and 6 Hard questions. DoorDash has a higher proportion of Hard problems in its interview set.
How should I prepare if interviewing at both DoorDash and MongoDB?
Start with the 6 shared problems since they cover what both companies ask most often. Then add 20 DoorDash-specific and 18 MongoDB-specific questions to round out your prep.