The entire process took exactly 2 weeks, which was amazingly fast and smooth.
My recruiter was really wonderful and went out of the way to make all of it happen. Some time after i applied to Snapchat, I received 3 exploding offers, so i only had about a week or two before i would have to accept the other ones. This made things really hard, but the recruiter was willing to bump up my onsite just to make the timeline happen. My recruiter was so good about communication and keeping me in the loop that we miraculously made my first choice company/offer happen!
The actual interviewers were all really nice and smart/knowledgeable, especially the last one. The interview questions aren't that much different than silicon valley style questions. You may need to brush up a bit on interviewing before applying; but otherwise, nothing too crazy.
Another note - if you were considering an offer in the bay area vs here, my advice is to actually come here. Looking at the list of all of the world's best startups - snapchat is the only one that you can come make an impact in and still feel rewarded for it. The move from the bay area really isn't that bad (a lot of people here go to the bay area every weekend since it's so close).