Tapad interview questions

I apply online. First is 15-20 minutes HR interview, next step is a technical phone interview, finally onsite interview. But I fail after HR interview. I think this company pays much attention to GPA, if your GPA is high, they will be very likely to give you an HR interview.

I applied online for the post. The recruiter contacted me withing a week and set up a phone interview. The phone interview went very well, I talked to one of the like minded person from Tapad and things progressed to second level. I was called for the onsite interview. To my surprise, instead of multiple people talking to me only one person talked to me for 30 minutes and walked me to the door. I was told that other person who was scheduled to take my interview is absent. After 3 weeks recruiter called to say I was let go for the position. I am still in shock that someone can interview you for 30 minutes within which most of the time I asked him questions about Tapad, how can they decide to let go? If my resume was not fit for the role, why bother to call me onsite?