Johns Hopkins Applied Physics Laboratory Instrument Embedded Software Design Engineer interview questions

A phone screen panel following by an on-site interview. They asked me to prepare a 20 slide presentation highlighting my experiences. I had to present in front of 15 people and then they asked me questions. It took me a lot of time to make this presentation and then the next day I got a short email telling me that they will not give me an offer. They did not give me any explanation why. I sent a few emails asking if they could provide feedback and I didn't get any response. I thought it was such a waste of time putting together the presentation. Most of the people in the group thought of themselves as geniuses and there was an aura of arrogance. Don't bother interviewing with this group...