The hiring manager called me up on phone and asked reasonable technical questions. Priority Invertion, Deadlock, Mutexes. Keep in mind that this was probably for a position which required very good OS concepts. I gave satisfactory answers and he arranged for a 1:1 the next week. The onsite interview had about 5 people. First one was hiring manager himnself. Gave a C test. Simple sorted array merging. I had rusty hands. Followed by another enginner who grilled me on OS concepts. How is executable format stored and loaded. Where are variables stored. How are interrupts handled etc. Majorly OS related stuff. Also recursion C questions. This was followed by another round of hard core questions on OS, threads and non amskable interrupts followed by a simple question on linked list. Need to know basics about datas tructures and algorithms. Which one is more efficient etc. After this a member from different team came by, asked some questions on my earlier work and another tree recursion program. This followed by the hiring manager of another team, asked basic question on my previous work and other problem solving scenarios when two processes are communicating with each other(IPCs). I was asked to come by for a second round after a week. The first 1:1 was difficult for me. Some questions on semaphores, mutexes. C programming question specifically targeting your knowledge of bitwise operators and memory management. Did not do so well. This followed by simple rounds by 2 other persons. Previous work. Multiple processor programming etc.. Overall, I probably needed more experience in the area that they wanted. Did not get the offer.