I applied online and then got an request for phone interview after a month. Then after another 3 weeks, I was invited to a one-day on-site visit. I was asked to deliver a 1-hour presentation on my PhD thesis. Then there were several 30 minutes meetings with all the PIs on the proposal. One thing you should be aware of is that Brookhaven National Lab is located in very rural area. In the evening before your onsite interview, the only place to get some food is an automatic vending machine at the Guest Center. If you arrive on weekends, it might run out of stock. The research group will probably treat you to dinner for your on-site visit. However, if that's not in the plan, It might be a good idea to grab some to-go food from the airport. I was the first candidate to be invited there and there were two other candidates whom they would like to see but hadn't worked out the schedule yet. So it took a bit long after my on-site visit before I got the offer. From the first phone interview, it took about 2 months.

online phone interview over skype, 1 hours talking including 30 mins presentation and 30 mins conversation. presentation is about my PHD work. I changed my phd defense slides a little bit. then all group members (PIs) asked questions according to my PHD work. because of my strong publication, they decide to offer me a position after online talk. no more onsite interview.