[Lanolderen]

In Germany I've seen both. Whenever possible I push for having everything in English. Code comments, general documentation, databases, etc simply because the german developers know English but the non-german developers sometimes don't know German. It also puts everyone at roughly the same language level since we don't have many English natives.

PS: I remember quite a while back when Wargaming's World of Tanks became a big thing they had to translate everything from Russian to English because they wanted to get foreign developers involved as well. Never heard of the reverse happening.