I applied online. The process took 1 week. I interviewed at Optiver (Amsterdam) in Feb 2021
Interview
The first step in the interview process is an online hackerrank challenge and you have 48 hours to complete it. You have to choose between Java, C++ or C#. It is a mixture of theoretical and a few implementation questions. I completed the questions in February 2021.
Interview questions [1]
Question 1
Validate a tree. I do not remember the question exactly but we were given a binary tree and we had to validate it given some instructions.
The interviews consisted of an OA, then behavioural, then technical and thena final round consisting of another technical, system design and behavioural. These last interviews all an hour each. I only got up to the first technical.
OA; quite long, 3 tests
Behavioral interview: just a short talk with HR, motivation,…
Technical Interview 1: fundamental CS, nothing more
Technical Interview 2: system design, very vague but just go with the flow
Technical Interview 3: live coding, still leetcode but optiver style is a very descriptive problem, but the main thing could be boiled down into only few lines
