Never made it to the second round of interviews. They started out with basic introductions, asked a tiny bit about my resume, then we jumped into a typical brain-teaser whiteboard type problem. I struggled with it a bit but tried to be open about my thinking process. It was pretty clear by the end of the problem that they were not interested continuing the interview cycle with me.
I'm not great with whiteboard challenge type exercises, because, well, solving brain-teasers isn't what I do day-to-day as a developer. I didn't brush up on this skill or do much practicing in preparation for the interview, but if I had spent a few weeks practicing I probably would have done better. I would encourage anyone interviewing here to make sure they're good at "leetcode" type challenges, and I think they'll do fine.