I had applied online through my school job portal. I got a response within 2 days to schedule a phone interview. The interview was rescheduled about 4 times within the next 2 days without even asking for my availability. Every time the google calendar event was changed directly. On the day of the interview, the interviewer actually called me 30 mins earlier and not at the scheduled time. Very unprofessional behavior on their part.
Also, the first thing the interviewer mentioned was that he won't be hiring us full-time, but would hire us as an intern for the first 3 months and then decide whether or not to give us a full-time opportunity. Honestly, this is where I had already made up my mind that this interview wasn't worth giving.
I didn't quite get the logic of rejecting me based on my grades. They aren't bad, but certainly I haven't been a person who has ever tried to maintain a 4.0 GPA. Rather than going through my resume and asking me about my projects, the interviewer just focussed on my grades which makes no sense.