CoL is often mentioned, but what's not is the saving rate.
Saving the same percentage in a higher CoL place gives you the option of moving out or retiring anywhere, including a high CoL location. You don't have these options if you make a lower wage at a lower CoL place.
Wouldn’t low engineer salaries encourage more startups in Germany? Relatively cheaper labor pool if the talent is good enough for Silicon Valley companies.
Heard mixed things about intra-company transfers from Europe to the US.
Otherwise it's rather difficult to get to SV.