After Round 2 I Asked Interviewer How he would Solution for Above mentioned Q1 & Q2 questions of the Round 2 Technical Interview. Very Smartly Interviewer Did not take any effort to answer and also told me find it out by myself :)

Regarding "( I Guess Interviewer also Not aware What he was asking ;) :P When he told sender is not aware of receiver hehehehe )" Have you heard about Middleware or ActiveMQ etc? Using message queues/ topics, sender and and receiver can communicate without knowing about each other, they need to know only about the destination. It is loose coupling of applications. Another way is to use DB tables for integration/communtication. Even here sender will not know about the receiver and vice versa. Don't make fun of people when you feel the question is stupid, because it is not the one who asked it, it is the one who don't know about it is the real stupid. Thanks.

Have you seen implementation of Broadcast (receiver and sender) in Android platform that is an example of loosely coupled such system and it will be working like [Sender] [Middleware platform] [Receiver] here middleware ie android frame work is aware of both sender and receiver but not these two component know about each other (receiver and sender are two component here)

The simple such kind of implementation is a broadcast communication over port, like twitter facebook or any share trading exchange works, that is port broadcasting (Twitter, facebook use the similar concept but not the port broadcasting), this can also be refer as observable pattern, I am also agree with the above answers specially with Srikanth's

If you Factory Design Pattern then Sender will not know the receiver other than creating object for the Factory method ... like that we can use Buisiness delegate pattern and service pattern....

The command design pattern to some extent is also a example of this kind of behavior where invoker and implementer are decoupled. So this is a very common scenario for loosely coupled architecture. I think that you should be aware that designs and patterns are evolving at a rapid rate and there would be various technologies to support this kind of behaviour