Had an initial phone call then a technical challenge. The challenge was very simple, and then they added a second layer to the challenge as well, which was also easy. However they were fairly ambiguous about a part of it, and generally you can ask interviewers if they're specifically wanting you to do X or Y. This interview was very awkward, they wouldn't confirm that I understood the question correctly and I went along implementing my solution. Only at the end did they confirm that they were wanting me to do the other implementation, not the one I did. Both were easy to implement though. This was apparently enough to pass on me. Very weird and obnoxious experience all-around. Get better interviewers who know what they are doing please.