I applied online. The process took 2 months. I interviewed at CERN
Interview
1st form to complete with personal information regarding your studies and CV
2nd optional video auto-recording presenting yourself and answering to questions regarding your soft skills
3rd Skype call with the team that wants to hire you, explaining the project you should be involved in and checking your fit
Interview questions [1]
Question 1
Coding skills checked through a shared coding environment. Task not too difficult in Java.
Then questions on CV.