A service like Transifex seems like it could help decouple translations from code, though I haven't seen how it works when using a remote translator.

I've almost* always had good luck over-doing it a little. Not a ball gown, but if you have a dark blazer, it shouldn't hurt to wear it with a skirt and stockings or some dress pants. I think it shows respect to put in a little effort. But I've interviewed folks in suits and ties, hoodies, and polo shirts. I've never heard someone comment on anyone's interview attire -- finding people who know their stuff is hard enough without worrying about their shirts. Good luck! *Exception: dress down some for a Nike interview. I felt uncomfortable walking around in fancy clothes.