I applied in-person. I interviewed at Area 23 (New York, NY) in Nov 2014
Interview
Interviewed with 3 CDs. Short portfolio review. Lead with the crazy, out there stuff. CDs were more interested in experiential stuff than the print stuff. Follow-up interviews were with ACDs--pretty much the same process. I was extended an offer within 2 weeks.
Tip: Don't hold back on the risque spec stuff. Show ideas that you want to pitch to potential clients.
I applied through a recruiter. The process took 2 weeks. I interviewed at Area 23 in Jan 2016
Interview
Brief phone interview with recruiter, scheduled interviews with 2 teams in the office, casual and relaxed interview, went over my creative work and discussed role/expectations of the position, quick response from HR afterward.