Applied at career fair, one of their engineers followed up a few days later. Came in for an interview about a week and a half later. First just talked with the engineer I had spoken with at the career fair. He asked me some basic questions and we went through a written test. After that the CEO and their head of Research and Development came in and grilled me about the languages I had put on my resume and Object Oriented programming concepts. Wasn't incredibly difficult, just go over your definitions.