Interviews: After applying to an advertised post and having a few phone conversations with my future group leader, I was invited for a site visit. Most candidates interview in a full day of 30-min one-on-one interviews with the hiring manager, staff in the hiring department, and staff and managers in other departments you'll be working with. I think the idea is for as many people as possible to provide their impressions of the candidate, the interest level of the candidate, and his/her fit with the group. You're interviewing with the technical staff you'll be working with, so the interviews were more conversational and focused on the technical work to be done on the job than your typical formal screening interview. The day includes lunch and dinner with staff, so be prepared for a long day! I've heard there is the option to break it up between 2 days, though. I found all the staff I met with to be open and honest about what they do and don't like about working at the lab, although you can pretty much guess what those things will be (government lab, so funding and research programs are at the mercy of congress, but you have a good work-life balance, etc). Job talk: Candidates also make a 45-min presentation to staff, including those who will be interviewing you. This is a good opportunity to persuade them that you can communicate a technical topic to an audience of technical people who may not be experts on your subject. It doesn't matter if it's different from the field you are interviewing for. I think the point is to show that you can assess a technical problem, propose a solution based on sound principles, and tell them what you found - and more importantly, what it means! Be aware that this is a national security lab and most positions involve various security screening. Ask your HR contact and the hiring manager to check into the security requirements for the specific position you're interviewing for. Do you need a security clearance (not everyone does)? Do you need to be a US citizen (not everyone does)? What if you have a dual nationality? It's their job to interpret the rules, after all! After: My future group leader and manager were up-front with their interest and keen to know my interest right away. They kept in contact with me all throughout the post-interview process of getting the offer through HR, checking references and education, etc.