I applied through an employee referral. I interviewed at American Express (New York, NY) in Jan 2016
Interview
Mostly behavioral, although one or two consulting-style case studies about market sizing/segmentation. Interviewers were very friendly and fair, did not expect a perfect performance in the case study. More about thinking creatively and solving methodically. Smart and relaxed people overall.
Interview questions [1]
Question 1
What is the market size for a new card to be released for millennials in the United States?