I applied through university. The process took 1+ week. I interviewed at Optiver
Interview
it's pretty chill, mostly open ended questions with a lot of behavioral questions. You get to talk to the CEO and the CTO as well. Only real technical questions are basic logic design questions
Interview questions [1]
Question 1
Design a system that takes traders ID/price and the buyers ID/price such that you submit an order if the ID matches and price is lower. I.e. a hardware priority queue