Wolfram Research Web Developer interview questions

I applied online for the position, the recruiter got back to me the next day to schedule a call. The first round, the recruiter asked me general questions like my experience, the projects I have worked on, salary expectations, job location etc. After that, she scheduled me for a phone interview with the head of Web R&D within in the week. It was a 30 minute phone interview which started with him asking for my background and then he gave me a link to an online collaborative coding platform. There were 2 coding problems and he asked for 2 solutions for the second problem - one in O(N) and one in O(N Log N). The platform we were coding on was crashing again and again, so we just talked through the first problem and he said that I should finish up all the problems and send him the code in an email after. I did so and the next business day, I got an email saying they were not going to continue with me.