I was shocked by how unprofessional the process was. My recruiter from the beginning was super flaky. They would not call me when they said they would and then call at completely random times catching me off guard. I appreciated that they tried to help me prepare for interviews, though, which they don't really "have" to do. Then, after the on site, they basically told me I had to commit to coming to Facebook before I would receive an offer. It basically seemed like the recruiter didn't want to go through the effort of filling out paper work if I wasn't going to come. This was pretty shocking after having spent a month jumping through all the hoops and spending basically a whole day on their campus for interviews. I was already leaning slightly toward another company and that really clinched my decision. Then when I told the recruiter I wasn't going to come they got really aggressive contacting me repeatedly over call/text/email trying to get me to change my mind. Still without giving me anything in writing! I was so shocked that a company with the reputation Facebook had would operate that way.