First was an interview with the hiring manager about the role itself, and then a culture interview with a panel of 3 employees who asked about my interest and style of working/collaborating.
Everyone was extremely nice, and I thought they had good questions for me in addition to thoughtfully answering my own questions. I believe that everyone I spoke to had been there for 10+ years, which was good to see.
Unfortunately, I was the only applicant who didn't already have experience with their proprietary software, but it seems like a great place to work.