One of the founders attempted to school me on some things I got wrong on a very complicated assignment. This was somewhat expected, since it was scheduled into the interview, and because I was given an opportunity, also scheduled, to review my work. Up to here, I was comfortable with the process of critique they'd designed, even somewhat impressed. But ironically, I had to stop the founder in the middle of his "lesson" to point out that he had confused the two different hardware flaws I was asked to explain in a sample blog post. He said it ultimately "didn't matter" which was which, even though explaining the mechanism of these hardware vulnerabilities was the point of the assignment. It's too bad, because everyone else I spoke to seemed competent and friendly. I feel sorry for the recruiters.