Citadel vs Epam Systems Interview Questions
Citadel lists 101 LeetCode interview questions while Epam Systems lists 46. They share 9 problems — 9% of Citadel's bank and 20% of Epam Systems's. Focus on the overlap first, then drill into 92 Citadel-only and 37 Epam Systems-only questions.
Overview
Preparation Strategy
Step 1 — Shared core: Solve the 9 overlapping problems first. These are the highest-yield questions for candidates interviewing at both Citadel and Epam Systems.
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 Epam Systems-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
9 Shared Questions
High-priority problems to practice for both Citadel and Epam Systems.
| Problem | Difficulty |
|---|---|
| LRU Cache | Medium |
| Merge Intervals | Medium |
| Best Time to Buy and Sell Stock | Easy |
| Group Anagrams | Medium |
| Trapping Rain Water | Hard |
| Median of Two Sorted Arrays | Hard |
| House Robber | Medium |
| 3Sum | Medium |
| Pow(x, n) | Medium |
Unique to Citadel (92)
Problems in Citadel's list that do not appear at Epam Systems.
Unique to Epam Systems (37)
Problems in Epam Systems's list that do not appear at Citadel.
| Problem | Difficulty |
|---|---|
| Two Sum | Easy |
| Longest Substring Without Repeating Characters | Medium |
| Minimum Operations to Make a Uni-Value Grid | Medium |
| Valid Parentheses | Easy |
| Move Zeroes | Easy |
| Longest Common Prefix | Easy |
| Longest Palindromic Substring | Medium |
| Merge Sorted Array | Easy |
| Valid Anagram | Easy |
| Rotate Array | Medium |
| Reverse String | Easy |
| Partition Equal Subset Sum | Medium |
Frequently Asked Questions
How many LeetCode questions do Citadel and Epam Systems share?
Citadel and Epam Systems share 9 LeetCode interview questions. 92 problems appear only in Citadel's list and 37 appear only in Epam Systems's list.
What topics overlap most between Citadel and Epam Systems?
The most common shared topics between Citadel and Epam Systems are Array (7 shared questions), Sorting (3 shared questions), Dynamic Programming (3 shared questions), Hash Table (2 shared questions), Two Pointers (2 shared questions). Mastering these areas prepares you for both companies.
Which company asks harder LeetCode questions: Citadel or Epam Systems?
Citadel has 5 Easy, 60 Medium, and 36 Hard questions. Epam Systems has 16 Easy, 27 Medium, and 3 Hard questions. Citadel has a higher proportion of Hard problems in its interview set.
How should I prepare if interviewing at both Citadel and Epam Systems?
Start with the 9 shared problems since they cover what both companies ask most often. Then add 20 Citadel-specific and 20 Epam Systems-specific questions to round out your prep.