First they email you to try and set up a possible interview. Next they bring you in for a one on one interview. They get to know you on a personal level and professional level . They ask why are you interested in the position you applied for and also why are you interested in working in the United Nations. They also ask about your past job experiences and how that prepared you to be successful in the job you applied for. After the interview, you have to wait and see if they are going to hire you. if they are going to hire you, they usually send an financial offer including medical clearance you have to get in order to be officially hired at the United Nations.