Hudson-river-trading C++ New Graduate Tech Phone Screen Interview Experience
Interview Experience
I recently had an interview for a C++ new grad position at HRT. The interview lasted 30 minutes; we introduced ourselves and then it quickly began. The question was: Design a game. The board has 9x9 d
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I recently had an interview for a C++ new grad position at HRT. The interview lasted 30 minutes; we introduced ourselves and then it quickly began. The question was: Design a game. The board has 9x9 dots, and sticks can be placed to connect adjacent dots. The top-left dot's coordinates are (1, 1), and the bottom-right dot's coordinates are (9, 9). The rules are that players take turns placing sticks on the board. Sticks must connect two adjacent dots. The game ends when a 1x1 square appears on the board, and the player who made the last move wins. Each round's moves need to print the board to std out. After writing the code, the interviewer asked me to run the program, reading the coordinates of the sticks placed by both players from std in. For example, inputting 1 1 1 2 means the player connected points (1, 1) and (1, 2). This question has a high degree of freedom; there were no test cases. The question itself is simple, but there are many things to implement. The most troublesome part was probably how to detect game ends. Ultimately, I used a brute-force search across the entire board (using a double for-loop to check if any of the 81 possible square locations were filled out). I successfully completed the code, but didn't have time to implement error checking, such as catching the error when two sticks are placed in the same space. I guess that's why I failed. Sigh, based on previous interview experiences, I thought it would be a C++ cliché interview, but it turned out to be a coding interview. Posting this here is just to accumulate good karma, please give me some points, thank you!
About This Question
This is a candidate experience report from a hudson river trading interview for a swe role (new grad level) during the phone screen round reported in 2025.
Difficulty rating: Easy
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About Hudson River Trading Interview Reports
This question was reported by a candidate who interviewed at Hudson River Trading. LeakCode aggregates interview reports from 10+ sources, including 1Point3Acres, Glassdoor, LeetCode Discuss, Blind, Reddit, Indeed, and Nowcoder. Each report is translated where necessary, deduplicated against existing entries, and tagged by company, role, round type, and reporting date.
Use this question as one calibration data point, not a memorization target. Companies typically rotate their question pools every 2-4 months; the exact wording of a 2024 question may differ from what you encounter today. The underlying pattern, difficulty level, and follow-up depth at Hudson River Trading are the higher-signal extractions to take from this report.
For broader preparation context, the Hudson River Trading interview process typically includes a recruiter screen, one or two technical phone screens, and a 4-5 round on-site loop covering coding, system design (at L4+ levels), and behavioral. Reports tagged on LeakCode show the round-by-round distribution and typical difficulty calibration. To browse questions filtered by round type and seniority, use the company hub linked above.
How To Practice This Type of Question
Solve similar problems on LeetCode under timed conditions (25-35 minutes per medium difficulty). The goal is pattern recognition: recognize the underlying technique (sliding window, two-pointer, BFS, memoized recursion, etc.) within 60-90 seconds of reading. Strong candidates verbalize their hypothesis out loud before coding, then iterate based on feedback. Weak candidates dive into implementation immediately, lose time on the wrong approach, and run out of time for follow-ups.
Companies update their question pools every 2-4 months. The exact wording of any given question may have been retired by the time you interview. Focus your prep on the pattern, not the specific problem. The patterns that appear in Hudson River Trading reports consistently are the ones worth investing in; one-off niche problems are not.
During Your Hudson River Trading Round
Apply the standard interview round template: clarify requirements (2-3 minutes), state your approach out loud and confirm direction with the interviewer (3-5 minutes), code with narration (15-25 minutes), test with concrete examples including edge cases (5 minutes), discuss optimization or trade-offs if time permits (5 minutes). This template is universally accepted across FAANG and adjacent companies; deviating from it produces weaker interviewer feedback signal.
The single most predictive failure mode in Hudson River Trading reports tagged "no hire": not asking clarifying questions. Interviewers are explicitly trained to weight this. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into code immediately. The clarifying-question check is often the first signal recorded in the interviewer's written notes.