Gentex will tell you up front that their hiring process is long and slow. I had two 1-hour long phone interviews, followed by a total of 12 hours of 1-on-1 onsite interviews. That was followed by a phone call from the engineering director to review how things went. The time spent talking with HR was odd. They go quite deep into your childhood and family life. Questions about your parents and their occupations, did you have a normal childhood, etc. The questions seemed somewhat illegal. The talks with engineers was typical of most interviews. I did get a sense of arrogance though.