I applied through an employee referral. I interviewed at American Express (Los Angeles, CA) in Apr 2015
Interview
The hiring process went very well, I spoke to a total of 3 people. The process first took place over the phone then they called me in to speak in person.
I applied online. I interviewed at American Express (Gurgaon, Haryana) in Jul 2014
Interview
It was a day long interview comprising of 4 rounds comprising of basic intro to Managerial round to Sr manager round and finally the last with the reporting head of controllership team. Overall conduct was quite participative and smooth. Post joining came to know the screening for my post was done for above 200 candidates.
Wonderful experience
Know a lot about the company and it's business lines, have a good answer for why Amex and be ready for a consulting like case question. After preparation you should be fine, just be sociable.