Nvidia visited our campus to hire interns.
One day process.
There were 3 rounds.
1st round : Technical and Aptitude test - 4 sections included C&C++, OS, DS, Quant questions. (There is sectional cut-off) The level of difficulty is average if you are thorough with your concepts.
2nd round : Technical interview 1 - Be prepared for questions on whatever you right in your resume. I was asked about my machine learning project in detail. The future scope was also discussed. Oops concepts, you need have your concepts extremely clear. They will keep on increasing the difficulty of questions for a topic if you answer the previous one correctly.
3rd round : Technical interview 2 - Again I was asked about my project (Again a detailed discussion). A few problem solving statements were asked. OS, process synchronization, memory management. Similar to the above interview, difficultly level increases with every correct answer you give.
It will be extremely difficult if your concepts are not clear. Others were asked about pointers, data structures, lex.