I applied in-person. The process took 3 months. I interviewed at CERN (Geneva) in Mar 2015
Interview
Submit an online application, with as much detail as possible, and answer some questions about your interest in cern and the thing you would like to do . Three very good reference letters from top individuals are required.
After the committee decided, I go contacted from the Hr that setup the interview with the supervisor. I was given a description of the project and a asked about previous experience and goals. A couple of technology related questions .
The interview took quite some time but HR was very helpful at their own pace.
Interview questions [1]
Question 1
What is CORBA , with as much details as possible, and what is your experience in building middleware.