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Hudson River Trading interview questions

67 questions researched across 2 Hudson River Trading seats in Algorithm Development, Software Engineering. Below are 12 of them.

Seats we researched

  • Algorithm Development InternAlgorithm Development · intern · 45 min
  • Software Engineering InternSoftware Engineering · intern · 45 min

12 Hudson River Trading interview questions

  1. What's the expected number of inversions in a random permutation of n numbers, meaning pairs that appear in the wrong order?

  2. In an onsite programming round you get an existing C++ trading-system codebase, a client and a server, that already supports adding and cancelling orders, and you're asked to implement modify. What do you look at first, and which edge cases matter?

  3. In the data-analysis round you get a heart-disease prediction dataset with features like age, weight and height, and a notebook with pandas and seaborn. What do you do before fitting anything?

  4. If you use virtual functions in C++, how do most compilers implement them, and what does a virtual call cost?

  5. Let's start with a game. You roll a die as many times as you like, adding up the numbers, and you can stop whenever you want and take the total in dollars, but if you ever roll a 1 the game ends and you get nothing. What's your strategy, and how would you work out what the game is worth?

  6. How would you check that answer with a quick simulation, and how many games would you simulate to trust it to about a cent?

  7. A simple total-probability question. Machine A makes 60% of a factory's chips, and 2% of them are faulty; machine B makes the other 40%, and 5% of its chips are faulty. What fraction of all chips is faulty?

  8. You flip a coin 100 times and get 60 heads. Is that statistically significant evidence that the coin is biased?

  9. You roll a fair die 100 times and take the average. Roughly what range will that average fall in 95% of the time?

  10. How many distinct ways can you arrange the letters of the word LETTER?

  11. I roll two dice and tell you at least one of them is a six. What's the probability both are sixes?

  12. Three numbers are drawn independently and uniformly between zero and one. What's the probability that the middle one is below a third?

What a strong answer does

The questions above fall into 1 kind. What a strong answer does differs by kind, not by question.

Technical12 of 12 above
State the intuition first; walk through the mechanics; make assumptions explicit; test a risk or edge case; connect the answer to the role.

55 more Hudson River Trading questions

The rest of the bank — 67 in total — is asked by the interviewer during practice, so you meet them the way you would on the day rather than reading them first.

Practise Hudson River Trading questions

How these questions were researched

Every question carries a provenance grade. Some were reported by candidates who sat the round, some come from the firm’s own published guidance or a source that trains for it, and the rest are written to match how this firm asks. Each seat is studied on its own — the round it actually runs, the order it runs it in, and what it is listening for. A Hudson River Trading round is not a generic behavioural screen, and practising one as the other is how people walk in unprepared.

Falas is not affiliated with or endorsed by any employer named. Simulations are independent practice based on publicly described recruiting formats.