Postdoctoral applicants have rated the interview process at NIH with 3 out of 5 (where 5 is the highest level of difficulty) and assessed their interview experience as 100% positive. To compare, the company-average is 79% positive. This is according to Glassdoor user ratings.
Here are the most commonly searched roles for interview reports -
I applied for a post doctoral fellowship position in one of the major research branches at the National Institutes of Health. This involved meeting various principal investigators and faculty members. I was also asked to present on my graduate research.
talk to everyone in the lab, give an presentation, answer questions, have lunch with everyone, and then wait for a long long time before any decision. And then you proberly got the offer, than wait another long time to process.