Citadel vs eBay Interview Questions
Citadel lists 101 LeetCode interview questions while eBay lists 62. They share 17 problems — 17% of Citadel's bank and 27% of eBay's. Focus on the overlap first, then drill into 84 Citadel-only and 45 eBay-only questions.
Overview
Preparation Strategy
Step 1 — Shared core: Solve the 17 overlapping problems first. These are the highest-yield questions for candidates interviewing at both Citadel and eBay.
Step 2 — Company-specific depth: Add Citadel-specific problems like Longest Non-decreasing Subarray From Two Arrays, Binary Tree Maximum Path Sum, Minimum Knight Moves and eBay-specific problems from the exclusive lists below.
Step 3 — Difficulty tuning: Citadel skews harder in our data. Budget extra time for Hard problems if you are targeting that company.
Difficulty Comparison
Top Shared Topics
17 Shared Questions
High-priority problems to practice for both Citadel and eBay.
| Problem | Difficulty |
|---|---|
| LRU Cache | Medium |
| Merge Intervals | Medium |
| Number of Islands | Medium |
| Sudoku Solver | Hard |
| Find Median from Data Stream | Hard |
| Group Anagrams | Medium |
| Merge k Sorted Lists | Hard |
| Best Time to Buy and Sell Stock II | Medium |
| Maximal Square | Medium |
| Alien Dictionary | Hard |
| 3Sum | Medium |
| Word Search | Medium |
| Pow(x, n) | Medium |
| Rotting Oranges | Medium |
| Reorganize String | Medium |
| Course Schedule | Medium |
| Open the Lock | Medium |
Unique to Citadel (84)
Problems in Citadel's list that do not appear at eBay.
Unique to eBay (45)
Problems in eBay's list that do not appear at Citadel.
| Problem | Difficulty |
|---|---|
| Remove One Element to Make the Array Strictly Increasing | Easy |
| Alternating Digit Sum | Easy |
| Partition Equal Subset Sum | Medium |
| Binary Gap | Easy |
| Minimize Maximum Pair Sum in Array | Medium |
| Minimum Window Subsequence | Hard |
| Design Skiplist | Hard |
| Subtree of Another Tree | Easy |
| Two Sum | Easy |
| Spiral Matrix | Medium |
| Top K Frequent Elements | Medium |
| Binary Tree Cameras | Hard |
Frequently Asked Questions
How many LeetCode questions do Citadel and eBay share?
Citadel and eBay share 17 LeetCode interview questions. 84 problems appear only in Citadel's list and 45 appear only in eBay's list.
What topics overlap most between Citadel and eBay?
The most common shared topics between Citadel and eBay are Array (11 shared questions), Hash Table (5 shared questions), Sorting (5 shared questions), Breadth-First Search (5 shared questions), Matrix (5 shared questions). Mastering these areas prepares you for both companies.
Which company asks harder LeetCode questions: Citadel or eBay?
Citadel has 5 Easy, 60 Medium, and 36 Hard questions. eBay has 10 Easy, 39 Medium, and 13 Hard questions. Citadel has a higher proportion of Hard problems in its interview set.
How should I prepare if interviewing at both Citadel and eBay?
Start with the 17 shared problems since they cover what both companies ask most often. Then add 20 Citadel-specific and 20 eBay-specific questions to round out your prep.