I applied online and after a week I got a call from HR.
There were three interviews, first with HR, second with HM, and final one onsite.
The first interview with HR asked me very basic question about TCP/IP protocols(layer seven protocols), and some personal questions.
The second interview with HM asked me regular question like introduce your self, why are you interested in this position, what you know about us, and tricky ones like something that disliked you in your last job, teamwork issues.
The final interview was mostly technical, it was based on layer seven protocols, deep understanding how HTTP and DNS works, some Linux questions, linux commands, how Internet works, how CDN works.