AppNexus Software Developer interview questions

It was a typical interview process. I was contacted by a recruiter and given a few problems to solve. They were not too bad and there was no time limit. After submitting the problems, I was contacted by the same recruiter that I was moving further in the process. I had two phone interviews which one asked my various computer science questions and another that went over my solutions to the problem. After the phone interviews, they flew me out for a full day of interviewing (I MEAN A FULL DAY OF INTERVIEWING).... I was then told I would hear back from them in a few days.

I was contacted by a recruiter through LinkedIn. The next day, I had a phone call with the HR, then a week later, I had a phone interview with an engineer on some technical questions. Three days later, I came to their office for a full day of interview. I got an offer the following week.