Competency based interview with reasonable questions. They explain the questions very well. You can easily ask to hear the question again if you don't understand. They also ask follow up question.

I was interviewed by 5 staff members, including the Representative of UNFPA in my country. They were very professional and at the same time approachable. It was a long interview, roughly 45min. Prior to this, I had performed an assessment, which was long and labour-intensive ( Questions covered a wide range of skills: writing an essay, translating docs...). Still waiting for an answer.