A course of 3-5 interviews with peers, supervisors, and people who would be direct reports. During the process, you can expect to meet with one or two others, but not a panel.
Interviews range from behavioral/performance-based to hands-on pairing activities. I had many opportunities to ask probing questions about the company and the people I'd be working with. For my interview, I travelled to another city in order to meet with the CTO in person. This is not typical anymore - most interviews are conducted 100% remotely.