ZEISS Group Application Engineer interview questions

I applied online and recieved an email to set up a phone screening interview. The interview was 30 minutes, very straight forward. Within the next day I recieved a second email in which they invited me to a second interview.

I was contacted by a recruiter via LinkedIn. She gave me some information about the position and we had a short phone screen. Several days later I spoke with the hiring manager. I then flew out to Minneapolis for the final interview. I had 2 hiring managers speak with me, one via virtual conference. After about an hour and a half, we took a tour of the facility. HR booked a turn-a-round trip, so I was up at 4am and didn't get home until 11pm. I think this seriously effected the quality of my interview. Additionally, I asked for feedback and was provided nothing constructive.