DoorDash vs IBM Interview Questions
DoorDash lists 78 LeetCode interview questions while IBM lists 115. They share 10 problems — 13% of DoorDash's bank and 9% of IBM's. Focus on the overlap first, then drill into 68 DoorDash-only and 105 IBM-only questions.
Overview
Preparation Strategy
Step 1 — Shared core: Solve the 10 overlapping problems first. These are the highest-yield questions for candidates interviewing at both DoorDash and IBM.
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 IBM-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
10 Shared Questions
High-priority problems to practice for both DoorDash and IBM.
| Problem | Difficulty |
|---|---|
| Single-Threaded CPU | Medium |
| 132 Pattern | Medium |
| Next Permutation | Medium |
| Two Sum | Easy |
| LRU Cache | Medium |
| Integer to Roman | Medium |
| Merge Intervals | Medium |
| Group Anagrams | Medium |
| Longest Palindromic Substring | Medium |
| Roman to Integer | Easy |
Unique to DoorDash (68)
Problems in DoorDash's list that do not appear at IBM.
Unique to IBM (105)
Problems in IBM's list that do not appear at DoorDash.
| Problem | Difficulty |
|---|---|
| Find the Smallest Divisor Given a Threshold | Medium |
| Gray Code | Medium |
| 3Sum | Medium |
| Exclusive Time of Functions | Medium |
| Minimum Operations to Make Columns Strictly Increasing | Easy |
| Fizz Buzz | Easy |
| Best Time to Buy and Sell Stock | Easy |
| Count Ways to Group Overlapping Ranges | Medium |
| Meeting Rooms II | Medium |
| Rotate Image | Medium |
| Minimum Absolute Difference | Easy |
| Minimum Operations to Make All Array Elements Equal | Medium |
Frequently Asked Questions
How many LeetCode questions do DoorDash and IBM share?
DoorDash and IBM share 10 LeetCode interview questions. 68 problems appear only in DoorDash's list and 105 appear only in IBM's list.
What topics overlap most between DoorDash and IBM?
The most common shared topics between DoorDash and IBM are Array (6 shared questions), Hash Table (5 shared questions), String (4 shared questions), Sorting (3 shared questions), Two Pointers (2 shared questions). Mastering these areas prepares you for both companies.
Which company asks harder LeetCode questions: DoorDash or IBM?
DoorDash has 7 Easy, 45 Medium, and 26 Hard questions. IBM has 33 Easy, 73 Medium, and 9 Hard questions. DoorDash has a higher proportion of Hard problems in its interview set.
How should I prepare if interviewing at both DoorDash and IBM?
Start with the 10 shared problems since they cover what both companies ask most often. Then add 20 DoorDash-specific and 20 IBM-specific questions to round out your prep.