Qualcomm Senior Systems Engineer interview questions

One phone interview with 2 questions. If you got it all right, they fly you to onsite. It's a one whole-day process with 4 to 5 rounds 1-1. Each person gives 3 to 5 questions from puzzles to actual engineering problems. One of the 1-1 is lunch interview.

They contacted me two months after I applied online. The first interview was technical which I easily passed. Then I went onsite to give a talk and for further interviews. I did great in the interview and two weeks later I got an email from the HR that I passed the interview and got a pending offer. We even discussed numbers. The HR then stopped responding to my emails. I finally chatted with hiring manager and it turned out that they had given offer to multiple people. Very unprofessional. Qualcomm is taking its path down to a 3rd tier company.