[yarcob]

Germany has a lot of high end car manufacturers and other industry, which means that there are a lot of experienced engineers in the country that they can hire. Most people also speak English well enough, which makes it easier to collaborate with US engineers (compared to eg. Spain, where many people really struggle with English).

[bryanlarsen]

If recruiting experienced engineers was a primary consideration, they would have built in Southern Germany rather than Eastern Germany.

[sho_hn]

All of the established domestic car manufacturers have significantly expanded their operations in Berlin in the last 5 years (though mainly R&D, especially software). Germany has relatively high immigration, and it's a lot easier to draw highly qualified immigrants to Berlin than to the Southern German countryside due to the youthful appeal and lower CoL of the city. The US, OTOH, has become more hostile to immigration over time. From a "competition for global talent" PoV, Berlin is a decent stake in the ground in many ways. Tesla also has plans to build an R&D site on the land of the recently shuttered Tegel inner city airport.

[karxxm]

Due to the highly specialized and high quality automotive industry, there are also numerous suppliers that Telsa tries to reach.

[kfprt]

Tesla vehicles are full of German parts. The most obvious instance is the turn stalk in the model S/X borrowed from Mercedes.