American Express vs Citadel Interview Questions
American Express lists 23 LeetCode interview questions while Citadel lists 101. They share 3 problems — 13% of American Express's bank and 3% of Citadel's. Focus on the overlap first, then drill into 20 American Express-only and 98 Citadel-only questions.
Overview
Preparation Strategy
Step 1 — Shared core: Solve the 3 overlapping problems first. These are the highest-yield questions for candidates interviewing at both American Express and Citadel.
Step 2 — Company-specific depth: Add American Express-specific problems like Minimum Deletions to Make Character Frequencies Unique, Maximum Equal Frequency, Divide an Array Into Subarrays With Minimum Cost II and Citadel-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
3 Shared Questions
High-priority problems to practice for both American Express and Citadel.
| Problem | Difficulty |
|---|---|
| Best Time to Buy and Sell Stock | Easy |
| 3Sum | Medium |
| Permutations | Medium |
Unique to American Express (20)
Problems in American Express's list that do not appear at Citadel.
Unique to Citadel (98)
Problems in Citadel's list that do not appear at American Express.
Frequently Asked Questions
How many LeetCode questions do American Express and Citadel share?
American Express and Citadel share 3 LeetCode interview questions. 20 problems appear only in American Express's list and 98 appear only in Citadel's list.
What topics overlap most between American Express and Citadel?
The most common shared topics between American Express and Citadel are Array (3 shared questions), Dynamic Programming (1 shared questions), Two Pointers (1 shared questions), Sorting (1 shared questions), Backtracking (1 shared questions). Mastering these areas prepares you for both companies.
Which company asks harder LeetCode questions: American Express or Citadel?
American Express has 8 Easy, 12 Medium, and 3 Hard questions. Citadel has 5 Easy, 60 Medium, and 36 Hard questions. Citadel has a higher proportion of Hard problems in its interview set.
How should I prepare if interviewing at both American Express and Citadel?
Start with the 3 shared problems since they cover what both companies ask most often. Then add 20 American Express-specific and 20 Citadel-specific questions to round out your prep.