HR contacted me to schedule a phone screen with hiring manager. Next week, the hiring manager skype me, asking questions about my resume and background, the coding question was not very difficult as long as you know basic data structure and algorithms. One day after that, HR told me that they want to schedule an skype onsite interview with three engineers. The skype onsite was similar to the previous one. I would say that all the interviewers are very nice to answer all my questions about the company and help you to solve the problem when I got stuck. HR is very efficient and extended me an offer two days after the skype onsite.