American Express outsourced external recruiting to a third-party. My interview process consisted of a phone screen, which was unscheduled. I didn't feel like she had enough technical knowledge about the position, skills and experience that she was looking for. My phone interview with the hiring manager and another manager was great. As a last step, I had an in-person interview, which was also a great experience.
Throughout the process, the recruiter repeatedly made admin/scheduling snafu, which should have been a red flag to me. Then, she tried to convince me to consider a more junior role for what she said to be "similar pay" (I found out later than the pay would have been much less and the benefit structure would have been anything but similar). The recruiter and another colleague of hers that I also interfaced with were very inconsistent in their communication (should have been another red flag). They both seemed equally confused when I asked them details about my benefits. I had to call a couple different numbers to find out about the 401k matching, bonus structure, and other benefits. Lastly, the recruiter flat out lied to me and said that my offer could not be raised any more due to it being somewhat in the higher end of the salary range for my band level. Later, I found out that my salary was in the lower end of the range. I would strongly suggest taking detailed notes throughout the process and to follow up with the hiring organization directly if you have questions.
Overall, the people at Amex itself seem to be very collaborative and competent. There's a great work-life balance. It seems to be a great company to work for if you are not concerned about banking top dollars but rather would like to explore different career options (lateral move is very encouraged), maintain an active life outside of work, and be happy at work.