Roofing contractor or deck contractor for my flat roof balcony?

I want to get my balcony/flat roof deck redone. I was gonna do it myself and just add deck tiles but some of the surface is uneven and water pools. I'm also not sure what material the surface is and since this house is new to me I want to be sure there is no damage underneath. Do I call a roofing guy or a deck guy? And if anyone can figure out what the flooring is that would be helpful for my online searching.

https://imgur.com/065y3kz