Berlin is the only true international city of Germany, and with its active startup and IT culture - ~20 hackerspaces, countless IT MeetUps, startup events, wel

Berlin is the only true international city of Germany, and with its active startup and IT culture - ~20 hackerspaces, countless IT MeetUps, startup events, well-known STEM research labs spread across 3 full and several applied universities and research institutes like MPI or Fraunhofer; industry research (Amazon) - the only place in Germany and one of the few places in Europe that is interesting for the HN audience. The areas you mention are only places to go if your startup wants to tap into the (indeed very established) mechanical engineering industry, or very specific areas of research. But definitely no place for people who have a more international view on things.