Citadel Securities Software Engineer interview experience

Got offer

Easy

Neutral

London, EnglandPosted Dec 2025 · Candidate report, summarized by Dataford

My interview felt pretty direct compared to what I’d expected from Citadel Securities.

I had a mix of topics that included some computer architecture, and the experience leaned more toward fundamentals than obscure tricks.

Most of the coding portion I saw was described as LeetCode-like for others, but for me the questions leaned more toward implementation and low-level concepts—things like network protocols and memory allocation. It wasn’t only about writing code to pass a test; I also had to be ready to explain what I was doing and why.

I didn’t end up getting an offer. The overall vibe was that if the basics were solid—especially around systems fundamentals—and I could talk

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