One onsite interview. You are given a paper contains several questions which covers linux commands, algorithm, network, security and database. They give you about 1 hour to solve them, and then an software engineer would come and talk with you about the solutions. The discussion was quite relaxing, you don't have to answer all technical details correctly. They're more interested in how you think about the problems. I got the offer immediately after the interview, so I would say they were pretty effective.

A phone interview will come first, normally without prior notice. Then an online test is used for testing the ability to code. Lastly, an onsite technical interview is conducted, where you need to do the questions given on a paper for an hour, then explain your solution to the interviewers.