I was referred in August, had a phone screen and then Skype interview, and then I had to wait until I was given a concrete offer letter in October. Part of the wait is due to the transfer of the security clearance (if you already have one).

Recruited by a recruiter as s/he saw my previous experience via LinkedIn. Phone interview, then Skype interview, then onward to an in-person interview at the work location of the client. Very organized and efficient!