Just be comfortable

I get my current job in a interview at coffee shop.

There is nothing special, just be confident, moderate, and be yourself. present your Skills well.

If you are technical person, don't need to wear very formal, just a little more formal than casual.

when I interview my pervious job, people said " you shall wear suits". Luckily I don't, that guy wear tee shirt and Jean, if I wear suits that just make myself fool :))