NVIDIA interview questions

I've applied online and received invitation from HR shortly. They've scheduled first phone interview with senior RnD manager. I was impressed by that person from first minutes of the interview, he seemed to be knowledgeable and experienced manager. We talked about my background, then he asked several basic question , for example atoi C function and counting amount of 1-bits in byte. Then we discussed NVidia-specific product and it's implementation, step-by-step. Knowing OpenGL could help here, but isn't necessary, it seems that graphic-unexperienced engineer can get through it too. Several days later, second phone interview was scheduled, with software engineer that reports to previous interviewer. He continued to ask me about graphic-specific products and implementation. Short time after beginning I got lost - I was unable to understand which stages are considered to be solved and what is the current problem we are discussing :) For that mess, I can blame myself to be not familiar with graphic world at all. And a little bit, poor call quality :) Naturally, after second phone interview I got no feedback not from RnD and not from HR.

3 phone interviews, code test and 9 in person interviews