I applied online. The process took 4 weeks. I interviewed at Jane Street in Mar 2015
Interview
Submitted a resume online, got a phone interview about a week or two later.
First phone interview was some fairly simple maths problems that got slowly complicated. Took about half an hour.
Second phone interview was very similar to the first (questions were a little more difficult) and also took about half an hour.
Third phone interview had a few non-technical questions, which was unexpected(!)
Then one long, open ended, math-based question, this lasted just over an hour.
Got cut after 3rd phone interview.
Interview questions [1]
Question 1
1st round: I'm going to roll two dice, we both have to pick a number and whoever's number is closest to the dice roll wins. Do you want to pick first or second? (there were a bunch more, but I can't remember them)
2nd round: You have the numbers between 1 and 30. What is the largest sum you can make by picking out numbers but only using each prime factor once. (eg. if you pick 6, you can't pick any other number with a factor of 2 or 3). (again, there were more, but I can't remember them)
3rd round: Explain your choice of major for this position? Why did you apply? Why are you interested in an internship at Jane Street?
You have a safe with six digits and a light. You can input a code, if you have between 0 and 3 of the 6 digits correct, the light will turn red. If you have between 4 and 5 of the 6 digits correct, it will turn yellow and if you have all 6 digits correct, it will open.
There is $10, 000 inside the safe, you can guess the code as many times as you want, but need to pay each time you guess, how much would you be willing to pay for each guess?
I had a phone screening call from a recruiter, they asked some standard probability questions, bayes rule, and expected value about dices. Overall experience was pretty good. Make sure you prepare your probability
Interview questions [1]
Question 1
Expected value, if throwing a dice, 2 dices and 3 dices with option to reroll.
I applied online. I interviewed at Jane Street in Nov 2022
Interview
Very smooth. Around 30mins first round 1hr for the second round. First round consisted of easier probability based questions. Second round was similar but harder and longer questions. The interview process if approached in a calm composed manner should be easier to analyse
multiple phone interviews and a full-day Zoom interview. Interviews got longer and longer over time, but every person was very kind and helpful with hints when I got stuck. The questions get harder as the rounds progress and generally don't have a closed form answer in the later rounds
Interview questions [1]
Question 1
they describe the rules of a game and ask if you want to play it based on your expected earnings