Comment by jorams

The company seems to be primarily in Germany (Aachen), with headquarters/holding company just across the border in The Netherlands (10km away in Lemiers, right on the border). That region is pretty economically integrated and I believe setups like this are fairly common to make use of the "business climate" of The Netherlands. Think taxes but also less bureaucracy. It looks like at least one of the founders also studied in Maastricht.