[TalnSG]

Aside from "Jap" being considered a seriously offensive ethnic slur in the America, there is another reason not to use the term in business no matter where you are.

Job interviews are usually rather formal and one is better off not to use slang. Shortening any word, such as Japanese to Jap, is slang. Even if the word used is not offensive to anyone, it is still considered substandard vocabulary and should not be used in a professional setting.

BTW the mention of business cards was made, but in case you don't know what was menat by the proper way to exchange them it means with both hands. Both hands to receive and both to present. And take a minute to read, maybe even comment on the content, to show respect and that you are not just taking it as a casual gesture.