Jane Street Interview Questions

Updated Oct 14, 2014
Updated Oct 14, 2014
448 Interview Reviews

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Interview Experience

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Candidate Interview Reviews

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  1.  

    Junior Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Interview Details

    I applied for a trader position off my college’s career site. They were prompt in replying. I received two phone interviews. The first was easy probability questions, but the second had more difficult questions. I did not get a final round interview. The younger guy I interviewed with was friendly but the older guy was really harsh/dismissive when I got something wrong.

    No Offer
  2.  

    Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied through college or university – interviewed at Jane Street.

    Interview Details

    Submitted resume through school recruiting website, learned that it had been accepted for an interview a few days later. Came in for a 30-minute one-on-one interview. First couple questions were mental arithmetic, and then there were two/three probability questions. Essentially you only get to the next round if you successfully solve all of them.

    Interview Questions
    • The classic 5 pirates/100 pieces of gold game theory question. Did not expect it.   Answer Question
    No Offer
    Positive Experience
    Difficult Interview
  3.  

    Intern Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied through college or university – interviewed at Jane Street.

    Interview Details

    I started with an on campus interview, the question asked was fairly standard, involved trees and their space and time complexity. Then proceeded to two rounds of phone interviews, both had technical questions that were not that difficult to implement but required some deeper thinking to implement well. Overall the experience was fine, though the process is very difficult as they are very selective with who they hire.

    Interview Questions
    • None of the questions were too difficult, just attention to detail is important   Answer Question
    No Offer
    Difficult Interview
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  5.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Interview Details

    This was for second round (phone interview), after a first round with a recruiter on campus. They emailed me 20-30 minutes after my scheduled interview time to say they were unavailable. Arranged to have interview later that day. Lots of probability questions (in both rounds).

    Interview Questions
    • How many commercial airplanes are bought in the U.S. every year? Give 90% confidence.   Answer Question
    No Offer
    Difficult Interview
  6.  

    Analyst, Trader Assistant Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

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

    Interview Details

    I applied online and got the phone interview invitation within a few days. The online application is the simplest I've ever seen. I applied to both London and Hong Kong office and the interview is from London office. A trader interviewed me.

    Interview Questions
    • The interview is not very hard. But I made mistakes in very basic questions. It starts with calculating the sum of odd numbers within 100.   Answer Question
    No Offer
    Average Interview
  7.  

    Systems Interview

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

    I applied online. The process took 4+ weeksinterviewed at Jane Street in October 2014.

    Interview Details

    I applied online and was emailed by a recruiter the next day. They asked me to pick a time for the first phone interview (all of which are technical). This interview didn't involve programming, but some questions about UNIX and my personal projects. The interviews moved very quickly, the recruiter was always in contact the next day or so. Both the second and the third interview involved coding on a shared editor. For the second one I had to design an algorithm for a non-surprising string related interview question, which has an obvious solution in O(n^2) time, but requires hashing for O(n). The third one required smart usage of two different data structures for the same data in order to get the benefits of both. After the phone interviews, I was asked for a date to go to their NYC office.

    While the phone interview questions had definite answers, two of the problems for the on-site interviews were open ended and seemed to serve the purpose of letting them see you tackle a problem when you don't know where to begin right off the bat. Since I have no prior functional programming experience, I was recommended to study some OCaml before coming over. However, to my (positive) surprise, for the interview that required me to use it, one of the interviewers brought in a cheat-sheet of OCaml basics and went over it. I was then asked to implement a function which was of appropriate difficulty for a beginner. After I had my solution up on the board, the interviewer put up a shorter solution and asked me which one is better and why. They both had the same time complexity, but it turned out that they actually use the solution I came up with, because it does not do any computations after returning from a recursive call, in which case the compiler knows not to allocate additional stack frames.

    All of the interviewers were kind and patient, had a sense of humor, and were extremely intelligent (it seemed some of them could've become supervillains but opted for arbitrage). Their office is very nice, reminds me of something a well funded silicon valley company would go for.

    Interview Questions
    • I'd rather not spoil the fun for other candidates. Time flies when you're sweating bullets.   Answer Question
    Accepted Offer
    Positive Experience
    Difficult Interview
  8.  

    Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied through college or university – interviewed at Jane Street.

    Interview Details

    Phone interview. Woman called and asked some basic questions about mental math and some coin flip stuff. They seemed arrogant and as such I did not want to pursue the job.

    Interview Questions
    • In world series, what are the odds it goes 7 games if each team equal change of winning.   View Answer
    Declined Offer
    Negative Experience
    Average Interview
  9. 2 people found this helpful  

    Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online. The process took 4 daysinterviewed at Jane Street.

    Interview Details

    Got asked 4 quantitative questions. They were progressively more difficult. I answered the first 3 correctly, without much time used. The last question, however, I couldn't figure out. The interviewer tried to help me, but between his accent and the noise coming from the background (his side), it wasn't useful. After about 15 minutes, he ended the interview.

    Interview Questions
    • (medium difficulty) If you have an asset that goes up or down 20% with probability 1/2, what is the probability that after n days, the asset's price is unchanged?   View Answer
    No Offer
    Negative Experience
    Average Interview
  10.  

    Trading Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Interview Details

    I submitted my resume online on their website. After talking to them at the career fair, I dropped my resume again and got an email in a few days about scheduling an interview. Interview process was about thirty minutes for the first round. Consisted of simple mental math, combinatorics, and probability. Be wary that this question was for the next following interview I did not pass.

    Interview Questions
    • You begin with $100. You flip a fair coin. Heads, you get 1$. Tails, your money gets inversed (i.e. first tails, your money is now 1/100). What is the expected value after 7 flips?

      (hint: recursion)
        View Answers (7)
    No Offer
  11.  

    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

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