I applied through college or university. The process took 5 weeks. I interviewed at Optiver (Chicago, IL) in Mar 2019
Interview
First a HackerRank and then phone interview to get the on-site interview.
On-site consisted of four parts: behavioral interview, two technical/critical thinking interviews, and a conversational interview with a senior data scientist. Overall, the experience was great. They handled all the logistics seamlessly.
First round is HR interview, all BQs. Second is Tech round, gave me a hard level Leetcode problem. Third round is a case study, I forget the detail but it is a really complicated problem, a lot of data details need to be noticed. My programming language is Python.
HR Phone Interview: All BQs
Online Assessment: HackerRank (prolly some python Qs just forgot)
On-Site Tech Interview: Probabilities and Statistics
Final BQ Interview
The whole process took about a month, casual interview vibe
Got an online coding test invitation immediately after submitting an application. It took three hours, but I didn't proceed to the next round. I don't remember all of the questions, but one was coding up a trader analyzer
