UST Validation Engineer interview questions

Applied through one of my friend who is already working with UST for Hardware/Device driver validation. It took 2 days to get call from HR. Total 3 rounds interview. 2 technical and 1 HR. 1st round is telephonic and 2nd round is Skype. Both technical rounds are good and challenging. Got offer letter after back ground verification.

phone call followed by in person interview, the an offer email. I would say that the process of hiring was easy but they made me wait for a month before i heard back from them