My interviews with NVIDIA went pretty well although I didn't get the offer. Here is the rough process I went through
1. Submitted my resume at Siggraph job fair in the year of 2009 in the August (of course)
2. Three weeks later, got an email from the nice recruiter for an initial phone screening.
3. One week later, interviewed by an software operation manager, asked about my expertise, and was told that he would forward my resume to the dev tech team
4. After a month or so (I thought I was rejected already), got another email from the recruiter for another 45 minutes interview with the hiring manager. All technical questions and I answered okay - for some of them, I only came up with reasonable but not best solutions.
5. Got an on-site invitation the next day and scheduled a day two weeks after.
6. Interviewed by 8 dev tech engineers. They are mostly PhD researchers & developers. Asked mostly technical questions related to their own background. For about 3 of them, I didn't do well - partly because background mismatch...
7. Get the rejection one week after.
All in all, I was happy with the experience. NVIDIA engineers are smart and nice