Open Systems interview questions

Talked to a hiring manager over the phone, they asked me to come in for an interview which was very pleasant however I may not have been a right fit based on a few interview mistakes of my own doing.

The interview process seemed quick to me. Received a phone call from HR to discuss the basics of my resume, on the spot I was scheduled for a phone interview with the hiring manager. Spoke with the hiring manager the next day, was called and scheduled for an onsite interview later that week, went back for a second interview the next week to meet with the CEO. Received an offer a couple days later.