Phone interview with HR is like bait, it starts off easy and friendly but quickly gets more difficult. The next phone interview with an engineer is a bit more challenging-you will get the fermi question-every time. If you do well on that they invite you for the insite interview. The day begins with a presentation to 5 or 6 enginners, then you interview with a few enginners for 45 minutes each, go to lunch with a few of them, and then you interview with a few more engineers, again for 45 minutes each. Some interviews are technically difficult, others are fairly relaxing, and others are a bit brutal, they are designed to see how you react to stressful situations. I felt I did fairly well during the interview process, but towards the end of the day I started to fade (thanks to the guy next door in the Hyatt Regency who was plagued with sleep apnea and was snoring obnoxiously loud all night and prevented me from getting ANY sleep the previous night). This lack of sleep caused me to slip up on the 2nd to last interview of the day; I slipped up on a few strange questions about the melting of ice cubes and how they would influence the level of liquid in a glass of water and about why when two trains are traveling opposite directions at the same interval why one train would pick up almost all the people yet the other wouldn't-very strange brain teasers not suited for someone who hasn't slept in about 50 hours. Case and point-get a good nights sleep, and if the person in the room next to you at the Hyatt is snoring-make sure you get your room changed. Walking out I felt like I had a 50/50 shot at getting an offer, I felt I was close, but that last interview killed me I think, all it takes is one bad interview and you may be toast...so try to keep it together until the end. The key point here is that even if your presentation is flawless and you do very well during all of the other inteviews and lunch, all it takes for them to "consider other candidates" is for you to have one bad interview. Good luck.