I started answering, interviewer interrupted and said i don't want to listen any real world example. Just tell me what is abstraction in java ? I started telling him about the abstract class and interface, he again interrupted and given 3 options a) Customer b) User c) Programmer And said choose anyone option A or B or C, for abstraction. I asked are these classes you want me to consider for designing. He said no just choose any one option. I said, I didn't get you. He said, just choose one option. I said, i cant choose option randomly when i don't get your context. He said, just choose one option, then i will tell you what is abstraction. And in all these discussion it was almost 10-15 mins over. After a think, I replied, I am supposing these are the classes and..... He interrupted again and said don't suppose anything, just choose one option. (I thought, i am sitting with any psycho person) Again i repeat my words to him, I cant choose option randomly, I am supposing these are your classes, So choosing option (b) User Bcoz, for any application, user could be a programmer and , user could be a customer. He said, No, programmer is abstract, coz he developed abstract class and he has to develop program in that way that other programmer cannot see his logic and implementation.(I was literally thinking to leave the room) In the discussion, I said abstraction is a one of the OOP's concept and as like a psycho person, he interrupted again and said, No, abstraction is not a concept. It has a implementation in JAVA. I said, yes every OOPS language implemented abstraction concept. He said, No only JAVA implements abstraction, other language makes you fool. (I was on my peak, to leave the room) But I listen to him, and then he started flaunting, you guys read java from such fake books like "Complete Reference", if you get sometime read Kathy Seiria. And not allowing to speak anything, In between of previous discussion, he said, Whatever you are saying, I am not gonna listen you. i just wanna answer, in option A,B,C. I said, first the requirement/need comes and then we started thinking of concepts and then implement in language. he said, big NOOOOO, none of the real world example exists they are useless, only java implement abstraction. Then, he has some multi-threading, some of them i cannot answered and some i really don't want to answered. I was only thinking about to leave the room. Conclusively, I can say, It was worst experience with IRIS till my 7 years of career. I have never seen such arrogant, psycho and rude person in interview panel. I think, you guys should choose normal person for interview panel. Who knows how to behave. Technically sound is different think, but first you should be good in ethical things. Thanks, wasn't selected in IRIS.