Optiver Senior Software Developer interview questions

The same as many Optiver has a fetish to Hackerrank, I have no problem with coding exercises, just please choose sane platform. Anyways, I had completed the exercise and am pretty sure my solution was 100 correct. I have never heard back from Optiver after submitting the solution.

I reached Optiver through an external recruiter. Initially, I had to complete an hackerrank evaluation (which I've passed). It was followed then my 1 HR interview and 3 online technical evaluations (which included a design interview). I was then invited to Amsterdam. Here's where everything starts to not work as expected. The Optiver recruiter completely ignored my two emails in which I asked clarifications about the onsite interview. I had to reach Optiver through my external recruiter to get the details. This delayed the interview by two weeks, I had Zoom chat with the Optiver recruiter two days before the interview and they informed me that I need to prepare a (powerpoint) presentation. As an advice, please schedule this Zoom meeting earlier. The onsite interview itself was fine. Optiver looks like a great place to work and I met really smart and interesting people. After two days, I got a negative response (from the Optiver recruiter) and in the emails they mentioned that it's possible to schedule a talk to discuss about the interview feedback. I reply to the email and ask them to schedule this chat. I got, again, no replies from their recruiter. Again, I had to contact my "external" recruiter and I was inform that my rejection was caused by (the lack of) cultural fitness. So, overall, the company seems like a great place to work. I just highly recommend them to improve their recruiting process. Completely ignoring (multiple) emails from candidates is absolutely not acceptable.