There was online test. 15-20 technical questions related to c,c++,data structures. 2 coding questions, you have to solve any one of them. mcqs were easy. coding questions were easy but required some thinking. There were two technical rounds. If they think your skills are not properly evaluated, they I'll call you for the third round. They asked questions about system programming, c, c++, data structures, networking, operating systems. basically all the CS fundamentals. If your basics are clear, you'll clear the first round. Second round was difficult. They asked tough questions about operating system and networking. For each round there was elimination. If you clear the second round they take HR round. They asked normal HR questions like strengths, weaknesses etc. Difficulty depends on your interviewer but they have the best selection process. You'll be evaluated throughly.