NVIDIA Senior Systems Engineer interview questions

I applied through linked/company portal. Due to Covid-19 all rounds were scheduled online on Zoom. I used a google doc to write the code as necessary. The first round was with the hiring manager. The discussion was about my past and current work, interesting problems encountered and solutions, a simple C program and basic understanding of data structures. The next round was scheduled after a week with an engineer. The discussion was about the details of my current project, Operating system based questions (synchronisation mechanisms, virtual memory concepts) and simple C programming string based question. The third round was scheduled again after a week. The interviewer gave some insight into the role, asked about my current work. He asked about spinlocks and semaphores, linked list based question. The result was a no-go after this.