Several rounds. Highly conversational. I have since learned that far and away, the most important quality to them is "culture". During the interviews by the senior leadership, they struck me as unauthentically bubbly and friendly. Rosy predictions about the future and growth of the company were given several times, but did not prove true over time. You can improve your chances in their interviews by applauding the values of the company and gushing positive enthusiasm. Challenging or critical questions are likely to work against you.