I was expecting something related to "Ashkenaz" since the word for Spain is "Sepharad" but I was wrong... :)
Interesting thought! It's also interesting that we take after the English word here rather than the German word. There are probably historical reasons for that.
I guess it is not so much English, but Latin.
Interestingly, this can be translated with two different English meanings. 'What do you do in Germany?' asks what work/activity is being done in Germany, while 'What are you doing in Germany?' would mean something like 'Why are you in Germany?'
"What do you do in Germany" could also be questioning "What is there to do" there, i.e. if I were to go there, what might I be able to do?