It makes my eyes roll when peers show up for work in shorts, sandals and t-shirts.
<><><><><
And the impact to their software engineering is what? Are you a better software engineer BECAUSE of your attire?
The best code I ever wrote back in the day was written wearing jeans and a t shirt.
I cannot prove that my code is better because of my attire.
My position is one in which I am sent to clients when they are in deep, deep sh*t. When they call for me there is a serious problem.
Now imagine being this client and having me show up dressed like a slob, or an overgrown toddler. Showing up well-groomed and well-dressed immediately puts them at ease and instills confidence in the people I will work with. It’s also a demonstration of respect and courtesy, in my opinion.
So, no it does not impact my performance directly, but it most certainly has some weight on whether our clients call us back again. And they always ask for me by name when they do.