There was a meet and greet event the night before - not super important to go to imo. Asked to bring a topic to a group interview. My interview was only 2 candidates, but that was because someone scheduled did not show up. They randomly select one person's topic and you discuss it for ~50 min. The interviewers moderate the discussion - the two present for my interview were both philosophy majors and they would probe your answers pretty in depth. Barely asked any questions about resume - only briefly in the last 5 minutes. With such a unique company culture, they're really looking for fit.