Interview mainly focused on the following things: 1. Programming Language: C/C++/Embedded C 2. Data Structure Using C 3. Data Communication & Networking Concepts 4. Microprocessor & Controller 5. Operating System The controller & processors changes industry to industry and according to application so they didn't asked any thing about it. Just overview. And Some Pins & their functions. 40% main question was on C & C++ deep programming concepts. As it is for software development so they throw the questions mainly on that. Function,Pointers, Structure, Memory Allocation, etc 20% question were on data structure.Stack & Queue, Linear Data Structure: Link list & Arrays. etc 25% question were on Operating system Concepts & Designing. Like Scheduling, Memory Management etc. 15% you can say were on Data communication and Networking concepts.Mainly question were on TCP/IP Protocol Stack. Ethernet Technology. Switch & Routers Concepts. etc