I had an onsite interview for a new grad engineering position at Asana recently. It's true that they test you on technical problems you don't know the answer to; sometimes it seems like they tested me on technical problems that had no answer. One of their interviewers, who was in charge of both conducting a one-on-one with me and explaining the programming questions to me, was very friendly but also had a hard time clarifying any of his questions for me. I didn't really understand him and it was obvious from his facial expressions that he believed that his explanations had sufficed from the very beginning. The questions were either too vague and could be approached from many different directions or were so specific that it was obvious the right solution would have to be found in an epiphany-like "aha!" moment of mathematical understanding. I was able to answer and program most of the questions. I have to say that I was really happy to receive feedback following my interview, which no other company did. My advice to Asana: Don't let any one interviewer dominate the experience of the interviewee (especially if you may have suspicious that the interviewer may be overly didactic or has difficulty explaining things.) Of course, that's just my experience. I ended up finding a good position somewhere else and think Asana's interviews were some of the best ones I had the honor of failing.