I saw their booth at my school's career fair and talked to several people there. They mostly talked about how their company runs, not what they do. Later they sent me an email requesting to set up an interview. I emailed them back and set up an interview During the interview I was asked several questions like "Do you know what we do?" in which I didn't know the answer to because their website is in "stealth mode" and contains no information about what they do beside that they are hiring and are a wonderful place to work. After that the interviewer bragged about their founder Charles Simonyi and their paradigm of intentional programming which is "knowing what the user wants before they want it" and "not machine learning or AI". After that he went on to explain the rest of the interview process and told me that he will email me to schedule a time for the first technical interview and to look at Glassdoor for some sample questions. The next business day I was surprised to receive an email telling me that "Intentional Software will not be moving forward with the interview process". I was very confused and replied with no response to this day.

The first phone screen is behavioral, then there are 3 more, which are technical. The first one focused heavily on knowledge of the company, so do your research -- what they do, what their purpose is, who their founder is, etc.