Depends on the setting, but in some settings I've felt overdressed and even gotten odd comments when dressing business casual. I interpret that to mean slacks a

Depends on the setting, but in some settings I've felt overdressed and even gotten odd comments when dressing business casual. I interpret that to mean slacks and button shirt, plus sport coat when weather warrants (but not a suit, and probably no tie). Less of an issue in Europe than in the US afaict, although the opposite could be an issue in Europe (wearing shorts to the office is fairly unusual in many countries, even for programmers).