Long and extensive, they make you go into the office and shadow (unpaid) other employees for over an hour across multiple days. They did not give any follow-up on the interview process whatsoever. Overall, very unprofessional, especially coming from the "largest staffing agency" in the USA. Do not waste your time, they do not hold any consideration for candidates. The lack of follow-up is a spit in the face, and they should improve their interview process. I am disappointed I wasted so much time/energy on these inconsiderate people.