A recruiter contacted me initially for a screening about 1 month after I applied on the website. First call was with the recruiting manager and then had 3 phone interviews. Received notification about 2nd round interviews at HQ in Bethesda and traveled up for another 6 interviews, followed up by 2 additional phone interviews (one with a peer, one with a direct report). It was a thorough but fairly organized process and took about 1 month once the initial interview took place. Offer came few days after last interview. Interview difficulty really varied based upon who the interviewer were. Some probed harder and asked more detailed questions about past experience and problem solving techniques, others were more interested in cultural fit and soft skills. There is ample opportunity to show your preparation through the questions you ask the interviewer.