Regional? A suit is the norm in DC for most industries, including software. I've only interviewed one candidate (in DC) who dressed casually. Two or three in suits w/out a tie or a blazer and dress pants. The rest were in a standard suit with a tie.

Bangalore was the opposite end of the spectrum. Not only casual attire but a casual attitude to the interview in general (cell phone on the bus, in the park, etc). I don't know if that would hold for local, in-person interviews, but was true for video interviews (development team is split 50/50 between DC metro and Bangalore, with managers in both locations).

At my employer, arm or neck tattoos would be noticed, but probably not impact a developers job prospects. Management might be a different story.

My wife is in banking and a suit is 100% expected at interviews. And tattoos covered. And piercings anywhere but the ear removed. A face or neck tattoo would likely be an immediate disqualifier for a job at HQ and probably also in their call centers or branches. Of course, they also dress true business casual every day (no jeans, men wear jackets, etc).