Meta Software Developer interview questions

Everyone was edgy when I started seeing people at Facebook, including the receptionists. Granted, job interviews tend to be critical, and we are the people who seemed to be begging for the highly-lucrative job positions. Then I saw this lady, who gave no self-introduction, no facial interaction, had only super-sharp look or pretended to be, who led me through these cold stairs, picked up a drink, and up to this tiny room, then started asking me questions. God bless her, turned out she was a software engineer, and may be the domain expert in my field. OK, so let's move on to programming, by which time I became edgy, too, knowing this lady sitting right behind me, feeling her freezing eyes examining up and down my neck, maybe my hair, too (I am a man). Did she notice my white hair as well? Anyway, the interview was quick (less than an hour), and I was let go. I knew there won't be any followup. Even if it does, am I willing to experience it again? What a fast way to ruin a day-off.

I'm a Master student at a top CS grad school. I was doing an internship in Bay area in August and I started my process just two weeks before my last day there. Therefore the whole process was pretty fast because they (and I) want to finish all interviews before I leave so that I don't need to fly all the way from the east coast. My friend helped me submit my resume. A few days later the recruiter contacted me via Email to schedule an initial HR interview. In this HR interview he told me great things about facebook and asked for my related experiences and why I would like to join facebook. He looks satisfied with my background and we moved forward to schedule a technical phone screen. The phone screen went OK. I managed to code the first question in an efficient way but failed to figure out any possible way to solve its upgraded version with more constraints. I received an email from the recruiter two days after the phone screen and was told I passed it. We scheduled an on-site interview in the same week. The onsite interview consisted of three tech interviews. Two of them focused on pure coding/algorithm questions. One of them focused on behavioral questions and a easier coding question. I did well in one pure coding and the mixed one. I did OK in the last coding one: did not finish writing my code but the major part is clear and correct. I did make some minor mistakes and corrected them after the interviewer pointed it out. Four days after my on-site interview, the recruiter asked me for two references. Two days later I received the offer.