I applied in-person. The process took 4 weeks. I interviewed at CEA (Cestas) in Jan 2015
Interview
Security instructions: leave all electronic devices at home or in a special case provided at the entrance of the site.
Get your guest badges, and wait for someone to fetch you.
In the room, nothing unusual : Greetings, CV checking, discussion about previous occupations, motivation for choosing this company...
Then knowledge check and discussion about a small part of a project.