I have a German kezboard (sic) but I run it in US mode. I have no idea how any programmer can use the standard German layout (and many I know use US keyboards).
This. All good manufacturers (Apple, Dell, Lenovo) allow you to spec US keyboards when you order.
macOS is good because of it's composing. You can compose umlauts by pressing option+u and then the "base" vowel, sz/ß is option+s. Same with accents, that's option+e/option+i and more. The Spanish ñ one is option+n, n.
I have a German kezboard (sic) but I run it in US mode. I have no idea how any programmer can use the standard German layout (and many I know use US keyboards).