I applied through an employee referral. The process took 1 day. I interviewed at European Commission (Brussels) in Sep 2016
Interview
The first interactions are by email and by phone. The interview went quite smoothly. Normal questions, in front of seven interviewees. No tricky questions, more general knowledge of the job and institution. Once that was done you have to get a medical check up. Then you get to sign a contract for 3 years.
Interview questions [1]
Question 1
Why would you like to work at the European Commission, what are your strengths and weaknesses, what was the last country to join the EU, basic non tricky questions.