Citadel Software Engineer Interview Questions
45+ questions from real Citadel Software Engineer interviews, reported by candidates.
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Citadel Summer 2026 SWE Internship Technical Phone Screen Experience
The first interview asked about merging k lists, but binary search can't be used because the space complexity needs to be O(k) instead of O(n). I just received my Superday offer after a month. Anyone
2026 Citadel Internship Timeline
Posting this because I see people asking questions about the process. If you have any questions, feel free to put it in the comments, and please don't DM. I can't provide my resume or specific intervi
completed OA waiting for result, I want to understand what they ask, as I couldn't find much about it online.
Citadel Fulltime SDE Tech Phone Screen Interview Experience
Recruiter reach-out, 90 minutes, 3 questions, all coding. The following content requires a score higher than 150. You can already view it. The first question was Li Kou, exactly the same as Liu Siqi.
Citadel Tech Phone Screen for Software Engineer Intern
The interview lasted 45 minutes. The interviewer seemed unfriendly, and I felt a lot of pressure. After scrutinizing my resume, they started asking technical questions. The first question was a simple
The task required refactoring and optimizing a convoluted C++ codebase within a 1.5-hour limit to prevent execution timeouts. The code relied heavily on obfuscation to conceal the actual logic, utiliz
First Coding Interview I was given a to reverse a given string. It was easy. void reverse(char begin, char end) { \t\t\t// to do function } void reverseString(std::string str) { \treverse(str.data(), str.data() + str.size()); } int main() { std::string str = "Reverse"...
So I gave the online assessment for Explore HRT, which is a 2-3 day program by Hudson River Trading for sophomores to get a hands on experience into how HRT works and learn about the field. There were
A data processing pipeline consists of n services connected in a series where the output of the ith service serves as the input to the (i+ 1)th service. However, the...
Hi, I had two coding rounds at Citadel. Round 1: I was asked one medium question: A list of currency relationships with exchange values. (BTC - USD) find the best exchange rate from currency1 to...
Just finished OA but didn\'t pass all the test cases. Tho I finished doing this, still wanna know how to solve Q1... 1. Hacker\'s Team \tSimilar to https://leetcode.com/problems/longest-increasing-subsequence/ \tThe transformation is there are 2...
Visiting Cities There are a number of cities in a row, and there are two bus lines that go between them. They both visit all cities in order, but one may take longer...
Citadel | Software Engineer | NYC | Feb 2020 [Reject]
Overview Interviewing for software engineering role at NYC office. Has 4 total rounds. ## Round 1 ### Question Tell me about the a exciting problem you had to solve recently. ### Question Write a producer class, which...
LeetCode #295: Find Median from Data Stream. Difficulty: Hard. Topics: Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream. Asked at Citadel in the last 6 months.
LeetCode #1801: Number of Orders in the Backlog. Difficulty: Medium. Topics: Array, Heap (Priority Queue), Simulation. Asked at Citadel in the last 6 months.
#127 Word Ladder
LeetCode #127: Word Ladder. Difficulty: Hard. Topics: Hash Table, String, Breadth-First Search. Asked at Citadel in the last 6 months.
#348 Design Tic-Tac-Toe
LeetCode #348: Design Tic-Tac-Toe. Difficulty: Medium. Topics: Array, Hash Table, Design, Matrix, Simulation. Asked at Citadel in the last 6 months.
LeetCode #150: Evaluate Reverse Polish Notation. Difficulty: Medium. Topics: Array, Math, Stack. Asked at Citadel in the last 6 months.
LeetCode #1004: Max Consecutive Ones III. Difficulty: Medium. Topics: Array, Binary Search, Sliding Window, Prefix Sum. Asked at Citadel in the last 6 months.
#155 Min Stack
LeetCode #155: Min Stack. Difficulty: Medium. Topics: Stack, Design. Asked at Citadel in the last 6 months.
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