I applied online. The process took 3 weeks. I interviewed at Jane Street (London, England) in Jan 2018
Interview
As I know there are 3 phone interviews and one on-site. I got rejected after the third phone interview. They were only interested in my problem solving abilities, I liked that. At the end of the phone conversations I had the opportunity to ask questions.
On the last interview I got this question:
Given cards numbered from 1 to 9 all flipped up and two dies. We throw the dies, if the sum of the numbers is greater than 9, we throw again. If the sum is less or equal than 9 we have the following options:
-flip down the card with the sum as a number on it or
-flip down two cards, showing each thrown number.
So if we throw 3 and 4 we can choose to flip down 7 or both 3 and 4.
If for example 7 is already flipped then we must flip 3 or 4. Similarly if one of the cards 3 or 4 is flipped then we must choose the sum. If we can't flip down anything the game ends and our score is the number of flipped cards. What is the best strategy?
The process began with serveral online tests for maths and logic. They gave a personal interview to get to know the candidate better and evaluate fit for the company/role, then held a technical interview covering maths and logic problems.
Fun and filled with unexpected questions. The questions rely on fast thinking and fast calculations, and sometimes intuition because there is no sufficient time for me to work through the whole problem.
We started with a bit of small talk, followed by some probability questions. Ended with some basic algebra questions, Make sure to ask questions if you have any. Good experience, feels like the interviewer was trading.