I usually just ask someone from the company I will be interviewing with. IMO, a suit and tie, especially for a junior developer type position is probably wrong

I usually just ask someone from the company I will be interviewing with. IMO, a suit and tie, especially for a junior developer type position is probably wrong UNLESS you are the sort of person that is 100% comfortable and natural in a suit, and even then I'd skip the tie. My goal would be to dress 1 step above the people you are interviewing with. Enough that you clothes help convey a sense of elevated status, but not so much they look at you and go "I don't want to work with some guy that wears a tuxedo to work". Based on my non-scientific observations over the years, the ideal outfit would be pressed khakis, ironed polo or button-down shirt, sport-coat. If the environment is one where the people dress a little nicer, then you fit in well and the jacket probably sets you apart. If it's uber-casual you can leave the jacket someplace and then you'll be dressed nicely, but still a touch above most of the people you're interviewing with. FWIW, I can't remember the last time I've work a suit to an interview in probably 15+ years, the last 10+ of that I've been working higher-level management type jobs, many times in sales-ish roles/departments. Also, respect to your parents, but their conventional wisdom is probably massively out of date with current job trends/cultures, especially as it relates to developer positions.