My experience is narrowed down to just one single round with the World Bank, since the previous interview rounds were with the outsourcing company that they collaborate with.
This round was one hour, I needed to introduce myself and talk about my relevant work experience through portfolio projects. 4 people attended the interview, there were questions from everyone from my future team, while it was still led by the Team Lead.
They all had a friendly approach toward me while successfully maintaining the professional atmosphere, which is a very lucky scenario for an interview in my opinion. They made their decision and sent me the offer on the same week.