I have 7 visible tattoos on my arms alone, so as I've begun the interview process, I got advice on this exact subject from my private lesson teacher, who's got a full sleeve. His general observation was akin to what people have said above: that for the most part, it only matters to keep them covered during the interviews and other formal events. But once you've sold the people around you on your merits, it's not going to matter on a day-to-day basis.