Hudson River Trading
Algorithm Developer intern
Application
A person reads the CV within about two weeks. The assessment is not sent to everyone: some applicants are rejected on the CV alone, and a perfect score is followed by a second CV screen.
Online assessment
Web form · 150 min, 3 tasks
A CodeSignal pre-screen in Python or C++: a count of numbers with restricted digits where n reaches a billion, a board game to referee from a list of moves, and a tree given as nested lists in two parts, the second opening only once the first passes. Seven days to sit it, hidden tests, no score shown. Near-full marks is the bar, and the same set recurs year to year.
Sit this round →Phone round 1
Virtual interview · 45 min
Zoom with the camera off and a CoderPad link. Five to twenty minutes on the CV, then two or three probability and statistics problems from a small bank, each with fresh follow-ups. After a correct answer you are asked for the intuition, sometimes a proof, and since 2025 for a ten-line simulation to check the number.
Sit this round →Phone round 2
Virtual interview · 45 min
Live coding in CoderPad with the camera on. Usually a game whose strategy you have to code inside a given skeleton (blackjack hit-or-stand, a card war, a guessing game, a market-making game), with follow-ups on the metric, the complexity and the edge cases; sometimes a dynamic programme in parts.
Sit this round →Superday morning
In-person interview · 2 × 60 min
A codebase round: a small trading system that already supports add and cancel, and you implement modify in the language you chose. Then a data round: a dataset with a prediction target in a notebook, documentation allowed, and the interviewer asking what you have found so far. Both are graded before lunch.
codebase roundSit this round →data roundSit this round →Lunch
If the morning scored too low, your superday ends here.
Superday afternoon
In-person interview · 2 × 60 min
An open-ended modelling conversation (how would a ride-hailing driver earn more; where to put bike-share docks): hypotheses, what data you would collect, how you would model it and how you would know you were wrong. Then a maths round above the phone-screen level.
modelling roundSit this round →maths roundSit this round →Hiring manager
In-person interview · ~30 min
A conversation with the manager of a team you would rotate through, last in the day for full-time candidates and sometimes for interns: how you heard about HRT, a time your work was criticised in front of others and what it changed, how you work in code you did not write, and your questions. It is not scored by a rule, but it can reject you.
Sit this round →Decision
Feedback in a day or two at best, four weeks at worst; a lunch dismissal is the same-day answer. Rejection carries a cool-down of six to twelve months. Every round can veto; finishing the day is a good sign but not an offer.
Reconstructed from first-hand candidate reports and the firm's own published material. Problems in this track are original and format-faithful; nothing is copied from a live interview.