Interview Experiences

Real candidates, real loops: every round, what was asked, and how it ended.

Share yours, earn XP

6 stories

Likes earn the author +10 XP for the first 3 likes each day

CitadelData Scientist
Apr 2026

Temperature Models, Interpolation, and Streaming Regression

First question Background You are given daily temperature data for P towns and daily temperature data for New York City over the same N days. Write functions to answer several questions. Part One — five questions Q1: Which place, either one of the towns or New York City, has the greatest temperature variation, measured by standard deviation? Q2: When Town2's temperature is between 90 and 100 degr…

Technical Screen0
CitadelData Scientist
Feb 2026

Interviewer Freezes Mid-Screen, Then Asks Me to Estimate a Constant

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Technical ScreenXP0
CitadelData Scientist
Jan 2026

A Late, Awkward Interviewer and One Linear-Fit Question

The technical interview was supposed to be 30 minutes, but the interviewer showed up 5 minutes late. Fine, whatever. Then he introduced himself, and the whole thing was really awkward — he stumbled over his words the entire time, and all he actually said was his name and his job title. Then he just froze there, like maybe he was supposed to say something about the company, but he said nothing at…

Technical Screen0
CitadelData Scientist
Nov 2025

Battleship Design and an Async DAG Optimization

Sharing two questions I got when I interviewed for Citadel EQR in November 2025, for anyone preparing. It was a while ago, so this is mostly put together from memory. Question 1: Battleship design This one was mainly a discussion about how to design Battleship. I started from the basic classes and interfaces, then talked through the game operations, the board state, and how to determine whether a…

Technical Screen0
CitadelData Scientist
Oct 2025

Five Rounds of Live Math and Python From Scratch

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CitadelData Scientist
Oct 2025

Cold Applied, Wildcard Matching Live Coding, Rejected Next Day

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RejectedTechnical ScreenXP0

What are interview experiences?

An interview experience is a candidate's own account of a hiring loop — not a question bank entry. It tells you the shape of the process: how many rounds there were, what each round actually tested, how long the gaps between them ran, and what the recruiter said at the end. That context is the part a question list cannot give you.

How to read them

Weight recent write-ups more heavily — interview loops change, often within a year. Read several for the same company and role rather than one: a single account tells you what one interviewer asked, while five tell you what the bar is. Note the outcome badge too, since a rejection write-up usually explains the gap far more precisely than an offer one.

Share your own

Every published experience earns 50 XP, and each of the first 3 likes it receives in a day earns you 10 XP more. Likes must come from established accounts; like-for-like swaps and likes from your own second account are not paid. Write it while the details are fresh — the round order, the exact prompts, and how much time you were given are what the next reader needs.

Share your experience to earn XP