X Software Engineer interview questions

I applied online and was soon given a coding test to assess my abilities. I passed the test and was invited to a first-round phone interview which I passed. Very soon (only a few hours) after, they told me that they were interested in a second-round phone interview, which I did. They then sent me a survey and told me they'd get back to me in the next few days. Because previous communication had been so prompt, I already knew that I had not advanced when I did not hear back from them within 2 days. By the third day the emailed me telling me that there were no positions available for me. What frustrated me was that the second phone interview had been a very easy question, but I momentarily blanked and thus was a bit slow in answering, and that was what blew it for me.

Referred by an employee, get a hello email from recruiter with a link to online test. There are two problems to be solved within 1h, and I think I did not do well for the second problem.