I applied online. I interviewed at INTERPOL (Lyon) in Oct 2017
Interview
After passing a security screening which took over a month, I was invited to take a written assessment exam that was 2.5 hours (and included a quantitative section). Within an hour of submitting my exam, I was invited to an interview with HQ after a few days which was conducted over Skype. They're very thorough and rigorous.
Interview questions [1]
Question 1
How would you manage an unexpected situation that you weren't trained for?