I applied online and got an offer for interview after about 1~2 weeks. First it was by the internal HR manger, then it was by the hiring manager and then head of HR at the end. I was applying from a location in Asia so the hiring process might be different than the headquarter in the US. Once the interview was done, the whole process only took about a week until I hear my offer.

Some general questions: the recruiter has a nice attitude towards interviewees, and competition is extremely fierce; you need to pass 5 rounds, and then you may get the offer. Good luck to all.