I applied online. The process took 4 months. I interviewed at American Express in Oct 2015
Interview
I don't think AMEX has any formal interview processes. It totally depends on the unit you are applying for. For me, first round is phone screen, then group phone interview, then hiring manager interview.
I applied through a recruiter. The process took 5 days. I interviewed at American Express
Interview
Recruiter reached out me to out of blue and said would you be interested in this role. She did a good job explaining the opportunity, and also gave a good overview of what to expect.
Things moved at a rapid pace once they found me suitable for the role, a 15 minute call with hiring leader, an hour technical phone interview (some coding exercise) followed by 3 onsite interviews (technical, cognitive and manager). The whole process was transparent and quick, the whole crew were professional and friendly making the whole experience a pleasure.
Interview questions [1]
Question 1
Finding reachable vertices for every vertex in a directed graph