AppNexus Technical Account Manager interview questions

I went through a series of phone calls and an almost 5 hour interview process at the company itself with 5 team members from various teams. I appreciated how thorough and challenging the interview process was, but once you've spent so long having difficult interview after difficult interview with only one break in between, it can become very tiresome and I felt like my performance had dwindled by the end of the process. At the same time, maybe this was indicative of the fact that I wasn't right for the job...

I had one phone interview with the EMEA director, then met three people for 1h30 interview. They were very polite and professional. Unfortunately I think they're looking for people with an ingeneering background even for jobs that don't need it, their standards are too high.