The rules for most office workers about what to wear are fairly simple. In some industries - investment banking, for example - a suit is the daily uniform. For many industries, business casual is the name of the game. Technology, however, can be a little different - and a lot more confusing!
What you wear needs to consider:
- Company culture
- Local tech culture
- Your position
- Your desired position
What Your Clothes Say About You
Your clothes tell everyone who you want to be in the company, and who you are as a person. Dressing like your peers makes you a member of the group. For development, that frequently means jeans and a button down or a t-shirt. Which t-shirt you wear matters, too. If you work for a hip web startup, you probably don't want to walk into work with an Exchange 2010 t-shirt on. Walking in with a hackfest t-shirt is probably just fine. The former says you're "corporate"; the latter says you love to code.
Then there's the overdresser (confession: I'm an overdresser). The overdresser generally dresses one or two levels more formally than the rest of the team. As a developer, instead of wearing jeans and a button-down, I might wear slacks and a button-down. Or I might go two levels up and wear a tie or a blazer with it.
When you overdress occasionally, it means you have to do an interview or see a client. Overdressing consistently tends to be seen as having management aspirations. The team knows you're setting yourself apart with clothing, even if it's subconscious.
Lastly, there's the quirky dresser. This one is most common in very casual environments and startups. The quirky dresser has a distinct style and flaunts it. This is the worker who wears a kilt and combat boots (I actually worked with someone who wore this to work regularly, with a "got root" t-shirt). This is the person who wears a different tie every day, or the person with a penchant for vintage dresses. This look doesn't say, "I want to be in management." It says "my job lets me express myself through clothing, and it doesn't interfere with my code one bit!"
Button-Down or Hoodie?
What you wear to work every day tells your team and your bosses a lot about you. It tells your team if you're "one of the gang" or if you consider yourself a little bit separate. It tells management if you want to be put in front of a surprise client that shows up, or if you want to stay in the back with the team.
If your company has a dress code and it says "business casual", then the choice is easy. Wear business casual. If your company has no formal dress code, then things get more complicated. Dress like the people you want to have as peers; the message will come through, loud and clear.