Citadel Coding Interview Questions (2026)
Most-reported questions and how to practice them
89 coding questions reported by candidates for Citadel, sorted by how often they were reported. Source: community-sourced LeetCode company lists.
What the Citadel question data shows
Of the 89 questions reported for Citadel, 61% are medium, 33% are hard and 7% are easy. The most reported are Sliding Window Maximum, Palindromic Substrings, Count Palindromic Subsequences, Best Time to Buy and Sell Stock, LRU Cache.
This list comes from community-sourced LeetCode company lists. It covers coding questions only. It does not tell us how many rounds Citadel runs, what each round covers, or what it pays, and those change by role, level and team, so we do not list them. Ask your recruiter what each round covers, and check the company's careers page.
Prepare for the rest of the loop with the coding interview patterns guide, the system design framework, and the STAR method guide. Written by Kieron.
Practice what you read with a free AI mock interview, see how the tools compare in our AI interview copilot comparison, or check Aissence pricing.
Citadel Interview Questions
89 LeetCode questions — sorted by frequency. Question frequency is community-sourced from public interview reports and may not reflect the current process; verify details with the employer.
Last reviewed: September 5, 2026 · Source: LeetCode company-wise interview questions (community reports) · Reviewed by the Aissence Editorial Team.
Sliding Window Maximum
Palindromic Substrings
Count Palindromic Subsequences
Best Time to Buy and Sell Stock
LRU Cache
Find Median from Data Stream
Maximum Total Damage With Spell Casting
Minimum Costs Using the Train Line
Best Position for a Service Centre
First Completely Painted Row or Column
Minimum Operations to Make Numbers Non-positive
Maximum Length of Repeated Subarray
Merge Intervals
Number of Orders in the Backlog
Find the Duplicate Number
Insert Delete GetRandom O(1)
Evaluate Division
LFU Cache
Length of Longest Subarray With at Most K Frequency
Parallel Courses III
Tips for Success at Citadel
Start with the 30 most reported Citadel questions, then work down the list.
Mediums are the bulk of the list (61%), so spend most of your time there.
Time yourself: 20 to 30 minutes per medium, then explain your solution out loud as if to an interviewer.
After each problem write down the pattern and the signal that revealed it. Patterns transfer to problems you have not seen.
Pair coding practice with a system design framework and prepared behavioral stories; most loops include more than coding.
How to Practice for Citadel Interviews
Practice answering out loud with an AI interviewer built from your resume and the job description, and get a score and specific fixes for each answer. We are not affiliated with Citadel, and the mock interview is general practice rather than a simulation of Citadel's own format.
- ✓ Free mock interview built from your resume and the job description
- ✓ Desktop Interview Copilot for live interviews, where the rules allow it
- ✓ Behavioral practice with feedback on structure and specifics
- ✓ System design practice with follow-up questions
Frequently Asked Questions
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