Jane Street

  www.janestreet.com
  www.janestreet.com

Jane Street Software Developer Interview Questions

Updated Oct 1, 2014
Updated Oct 1, 2014
9 Interview Reviews

Interview Experience

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Software Developer Interview

Anonymous Interview Candidate
Anonymous Interview Candidate
Interview Details

Applied online with my resume and cover letter and got an email a few days later. Set up a phone interview, and they had me code on stypi.com. They asked about memoization techniques, as well as cache replacement strategies and time and space complexity of algorithms. They were friendly and allowed time at the end for my questions. The whole interview lasted about an hour.

Interview Questions
  • Implement the least recently used algorithm for replacing the contents of a cache after a cache miss.   Answer Question
No Offer
Positive Experience
Difficult Interview

Other Interview Reviews for Jane Street

  1. 1 person found this helpful  

    Software Developer Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online. The process took 2 weeksinterviewed at Jane Street in September 2014.

    Interview Details

    Applied online. Immediately got an email for a phone interview. The phone interview consisted of one programming question in OCaml. The interviewer was pretty quiet and didn't say much during the coding part. At the end of the interview, I asked the interviewer questions about the hiring process, internship program, etc.

    Interview Questions
    • Write a function in OCaml that when given a list of prices, returns the indices of when it is most optimal to buy and sell the stock.   Answer Question
    No Offer
    Neutral Experience
    Average Interview
  2.  

    Software Developer Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online. The process took 2 daysinterviewed at Jane Street in February 2014.

    Interview Details

    Phone Interview starting with the interviewer talking about himself and then we jumped right into the programming question. Afterwards we followed with any questions I had.

    Interview Questions
    • Find the smallest sublist size in a list of lists. Then after I came up with an algorithm that used List.length to compare which is an O(n^2) algorithm, he asked how could this be improved, which stumped me.   View Answer
    No Offer
    Positive Experience
    Average Interview
  3.  

    Software Developer Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online – interviewed at Jane Street in February 2014.

    Interview Details

    Self introduction. Coding on collabedit. Coding problem is designed for OCaml.

    Interview Questions
    • I was asked to (equivalently) transform binary search tree into array and vice versa. Note that they keep doing gambling with you. You have to bet the number that payoff expectation is positive by your mental math.   Answer Question
    No Offer
    Positive Experience
    Average Interview
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  5.  

    Software Developer Interview

    Anonymous Interview Candidate in New York, NY
    Anonymous Interview Candidate in New York, NY
    Application Details

    The process took a dayinterviewed at Jane Street in September 2011.

    Interview Details

    Very difficult, crammed as many software and programming questions in as he could in 30 minutes.

    Interview Questions
    • Write an append function in OCaml. (never used OCaml before)   View Answer
    No Offer
    Negative Experience
    Difficult Interview
  6.  

    Software Developer Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online. The process took a weekinterviewed at Jane Street in June 2014.

    Interview Details

    I submitted my CV online and got a response a few days later from HR. I was asked to name a few dates when I would be available for a phone interview. The interviewer called me on time. First question asked was if there were any projects I am proud of. The interview was getting technical later, and I was supposed to write code online.

    Interview Questions
    No Offer
    Positive Experience
    Difficult Interview
  7.  

    Software Development Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Interview Details

    There was 2 phone interviews and then a phone interview where one write code in google docs

    Interview Questions
    • Given an oracle that decide if a Turing machine halts. Create a algorithm that uses this oracle at most twice. The input of the algorithm is three Turing machines, the output of the algorithm is the Turing machines that doesn't halt.   Answer Question
    No Offer
  8.  

    Software Development Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online. The process took 2+ weeksinterviewed at Jane Street in April 2011.

    Interview Details

    The process consisted of 3 phone interviews (I suspect that there is a last one in their office).
    The first interview was about general math and concepts of computer science/functional programming. I had a few brain teasers (7^3, number of edges in a cube, a classic dice roll exercise).
    The second interview was centered around designing algorithms, so mainly computer science related. The idea was to shuffle, sort and use arrays.
    The last interview was mostly puzzles, including a rather complicated dice roll exercise and a puzzle.

    Interview Questions
    • You have 2 identical plates which break when thrown higher than a specific number of stories. You are in a 100 story building. What is the least number of tries you must do to determine the story number after which the plates are broken when thrown off the building?   View Answers (7)
    No Offer
    Positive Experience
    Difficult Interview
  9. 4 people found this helpful  

    Software Developer Interview

    Anonymous Interview Candidate in London, England (UK)
    Anonymous Interview Candidate in London, England (UK)
    Application Details

    I applied online. The process took 3 weeksinterviewed at Jane Street in March 2010.

    Interview Details

    I got the interview by emailing my CV. I first had a couple of phone interviews, then an interview on-site in London, then a half-day of interviews in New York.

    Most of the interviews involved whiteboard coding (in OCaml), plus there were some general programming questions and a few maths/probability questions.

    Interview Questions
    • Discuss the performance of garbage-collection algorithms.   Answer Question
    Reasons for Declining

    I really liked the company and they made me a very good offer, but in the end I decided I didn't want to leave my current job.

    Declined Offer
    Positive Experience
    Difficult Interview

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