So, my friend reffered me there. I went through a telephonic followed by a one on one round. The process was quite short and nice. Telephonic guy: He was very dominating and won't let me speek. His favorite words to cut my answers were "Listen carefully" One on One guy: He has no idea how to convey a question to someone. I had to ask the scenario three freeking times. And may be that's the reason he rejected me. But After asking third time, I was man........ you could have just said explain Observer design Pattern. But hey I explained the half of your problem. It's okay :p