I applied online. I interviewed at OSCE (Belgrade) in Jan 2020
Interview
Quite simple, largely administrative and formal with several tasks for which you can use the internet as a reference. Interviews is where you need to demonstrated knowledge of the subject-matter in a discussion, though do not expect to receive an offer if you do not know someone working at OSCE, as most jobs are hired through personal referrals.
Interview questions [1]
Question 1
How you handled stressful situations and conflicts with colleagues at work.