First a telephone screen by the recruiter, then a telephone interview with the hiring manager.
The telephone interview included questions about my work experience, and questions to gauge cultural fit and salary requirements.
The 4 hour panel interview was in their office with people from various departments that I would be interacting with. Each person met with me for about 30 minutes.
Questions ranged from friendly just get to know you, to more in-depth such as "How do you handle XYZ type of problem?" and "Describe your process for ABC?".
Although it was obvious that everyone was extremely busy, everyone was also welcoming and friendly. They were always checking if I was comfortable or needed anything. Overall a positive experience.