I applied online. The process took 6 weeks. I interviewed at Jane Street (London, England) in Feb 2017
Interview
The process was overall positive.
The person of contact is responsive, and if you proceed to next round you will always be told on the next day of every interview. The application process is flexible to some extent as I changed my application from a summer intern role to a full-time one after the second round. Failed at 3rd round though, I still had enjoyed the interviews.
Interview questions [3]
Question 1
Round 1: Typical Question you can find here. Adding up odd numbers within 100, two painters paint at different speed to work together, what's the chance 12 coins tossed having an even number of heads. Totally 8 of them.
Round 2: If you have balls weighting from 1, 2, ... 40g, and you have a fair balance, how many of their weights you have to know in advance such that you can measure all the rest?
The process was structured and intellectually challenging. It typically involves an initial recruiter screen, followed by probability, mental math, expected value, and game-style problem-solving interviews. Interviewers focus more on reasoning, communication, and adapting to feedback than memorized answers.
Interview questions [1]
Question 1
You have two opaque boxes in front of you. At each turn, you may choose one of two actions:
Place: put one coin into one of the two boxes, chosen uniformly at random.
Take: choose one of the two boxes uniformly at random, take all the coins inside, and empty that box.
You play for exactly 100 turns. Your goal is to maximize the expected number of coins you collect.
What is your optimal strategy?
Several phone calls to go to the final round. The phone calls consists of mathematical, probabilistic brain teasers which was not that hard for a mathematics major. Final round was to harsh for me, strong mentality is required
Application
I applied online. The process took 4 weeks. I interviewed at Jane Street (New York, NY) in Apr 2026
Interview
Lots of expectation/probability questions. Make sure to study game-theory type question that involves expectations. Specific concepts in stochastic processes don't seem that important. The first two were relatively easy. Just make sure to ask a question if there is any uncertainty