I applied online. The process took 1 week. I interviewed at Jane Street
Interview
Only did the first round: brainteasers and probability theory over the phone. Very easy questions, but the nerves really got to me this time. I would make sure to practice enough to the point where you can do these questions in your sleep if you tend to get anxious.
Interview questions [1]
Question 1
Q: Suppose you want to calculate how long an escalator is. You have two times: the time it takes you to ascend the escalator while standing still, and the time it takes you to ascend the escalator while walking at a speed of x meters/second. Q: Some easy probability question on bounding the event of rain on a second day if it rained on the first. I'm sure there's someone else on here who gave a more detailed account. A follow-up required knowledge about union-bound if I recall correctly.
I applied online. I interviewed at Jane Street (London, England) in Jan 2026
Interview
I did a Zoom interview.
The interveiwer was kind and asked me some probability questions.
I stumbled a bit but answered correctly in the end. However, I didn't get an offer so maybe they want someone who answers straight away.
Interview questions [1]
Question 1
Startegy of changing a line.
Is this a realistic strategy? What would change in the real world?
Technical interview round 1 and 2. Two math problems/brain teasers. Round 1 is easy, but round 2 becomes more challenging. Problems are well designed with multiple follow ups. Interviewer super friendly and nice. Great people and nice culture.
Very friendly interviewer and relatively easy questions. Quite organised in their interview process, with clear guidelines as to how to approach the interview. Focus is to explain the rationale and not just get the correct answer.
Interview questions [1]
Question 1
Probability of raining on sunday or saturday based on individual probabilities. Give upper and lower bounds on the probability of the union.