I'll soon be attending an interview with a medium-sized tech company (in the hundreds of employees) in Australia that has its product based on Ruby on Rails. So a situation more casual than working at a global bank.
What's the typical dress code for interviews with such companies? I'm happy to dress formally, but I don't want to dress too formally, and I'm wondering if not wearing a T-shirt from a Ruby conference will put me at a disadvantage.
A general rule-of-thumb is to think about the dress-code you would use on a normal work-day if you get the job, then dress slightly higher than that for the interview. So if you would use a pair of jeans and a (t-)shirt to work, maybe go with your finest pair of jeans, a button-up shirt, and a nice sweater for the interview.
As far as the Ruby-conference t-shirt goes, your attendance at this get-together should be a point in your résumé anyway. There's no need to showcase this by wearing apparel from the event.
Now, for my subjective opinion on the t-shirt, I would likely disregard it as "trying too hard to impress" rather than "wow, this guy is really good at Ruby". Because at the end of the day, the t-shirt says nothing about your professionalism or prowess in the field.
The general rule is simply: Ask! Dress code varies a lot between companies, and depends on many aspects, such as company culture, local culture, culture of the business sector (banking vs IT vs manufacturing), job description...
So in general it is perfectably acceptable to ask about the dresscode. Typically you'd do it during the phone screen (if there is one), or in response to the interview invitation. Asking should not be counted against you, on the contrary, it shows that you want to be well prepared.
That said, here is my personal rule of thumb for a "compromise outfit" for a man. I'm from Germany, but this should be ok at least for most of Europe.
To make it slightly more formal, add
This outfit is nicely in the middle between informal style (jeans and t-shirt) and formal (business suit with tie). That way, it will not look hopelessly overdressed in a jeans-and-tshirt place, and will still at least show you made an effort to dress up, even if they expected a proper suit.
Still, the best option is to just ask.
I would say that the general rule for all job interviews is a suit, if the company seems informal then drop the tie.
The way that I see it is that you are effectively going into a room with people and asking them to give you $XX, would you give that amount of money to a guy in jeans and a t-shirt?
I guess for me atleast I I have a number of tattoo's going down my arms and I would rather that their first impression of me is not distracted by those.
Note: I also am a software developer with 13+ years professional experience.
You can be creative, flout conventions and still look nice for interviews. I had a friend who wore tailored button down shirts with ties jeans and dress shoes, and looked great. Me I hate ties and will not wear them so I typically go with a solid color tee or turtleneck with a suit. If you have a phd you can get away with an esoteric tee shirt (not related directly to the job) if you can find one that has to be explained (and still not understood by the receptionist). Such a shirt can be a way to show off your knowledge without bragging (because you understand it and think it is funny), but it can backfire in some situations.
