There was an initial phone interview, and then they invited me to their office outside of Santa Barbara to do an in-person interview. The in-person interview was a little unique -- they asked me to do a ~45 minute presentation on a project or two that I had done. It was fairly informal and they asked me questions throughout, sometimes just to go into more detail for whatever aspect of the project and sometimes more technical questions related to my project for me to complete on a whiteboard.
After, they gave me a tour of the facility to give me a better idea of the kinds of technologies they use and projects they work on. Though I didn't get an offer, it was overall a very pleasant experience. Small company and everyone seemed friendly and helpful.