I don;t think it is about the standard. It looks like they only want someone who has already worked with messaging servers. If you have not worked on that befor

I don;t think it is about the standard. It looks like they only want someone who has already worked with messaging servers. If you have not worked on that before, then you have nothing to worry. Sometimes it happens that what a company/group wants is not what you have to offer, even if you are a good programmer. With all the media hype regarding these unicorns, you feel let down. Shrug it off and move on to other companies. Java is just to make their own life easier, because they readily know the Java solution.