I was very disappointed by the interview process with American Express, a company I admire greatly. I was originally contacted by a recruiter on LinkedIn, who then passed me on to a different recruiter who scheduled time for a phone screen. The recruiter did not call me on our set day/time, and after several back-and-forth emails, the only time he could find for another 15-minute phone screen was a week later. I've spoken with several recruiters over the years, and I was taken aback by how rude and dismissive he was when we finally spoke. He cut me off when I was answering questions, and if I asked a question, he responded with a one-word answer.
Unfortunately, this process left a very bad taste in my mouth with AMEX. I believe these recruiters are contractors, but, if so, at least the one I spoke with does not represent the company well to prospective candidates.