An recruiter contacted me by email and ask me to do a phone interview. She asked me whether I am familiar with production engineer's work and 10+ initial screen questions. They are all about basic Linux and networking knowledge, like port number and tcp protocol, Linux commands. Most of them are quite easy but they do really have some tricky questions. Afterward, I was told that I had passed and would have one coding interview and one system interview before making the final decision.
The coding interview started about 1 weeks later. I was asked to code using stypi and there are two questions in 45 minutes. One is translate English to "Goat Latin" language with a set of predefined rules. It was not hard but I still spent 20-30 minutes on that, partly because I cared too much about the detail. The second question is more a shell-script coding, although I did not realize it immediately. I was asked to obfuscate local parts of email addresses found in all HTML files under a folder (also subfolders). Due to the time limit, I did not write a clean and complete code for it. But I discussed with the interviewers for the possible solutions (shell script + python regex operation).
Then the recruiter told me I passes the first round and we moved on to system interview, which began 5 days later. Since it is totally new to me, I read lots of posts in glassdoor and other interviewing forums and there are very useful. The interview questions requires solid knowledge about Linux, operating system, performance monitoring. They both starts with a relatively simple questions but ends with lots of followup questions. Try your best to be open-minded and always talk with the interviewer. They want not only an correct answer, but also how you get this solution.
Later that day I heard from the recruiter that the feedback seemed also great. After one week, they give me the offer. The salary is greater than I ever expected.
Pros:
The recruiter is super nice and willing to answer any of your question in a timely manner.
The interviewing schedule is very flexible. You can propose any date as you like.
The interviewers are quite smart and patient. They are always on your side and trying to guide you through difficulties.