Myself, I sort of do both bottom up and top down programming. Usually I start at the top and write out high level code as if everything I needed magically exis

Myself, I sort of do both bottom up and top down programming. Usually I start at the top and write out high level code as if everything I needed magically existed. That helps me think about what I want and how I think I'll use it and that helps and clues me in to what low level stuff I need to build. Then I start to think about how to build those things and that usually goes bottom up. I do this iteratively. When I get stuck I go back to high level top down, figure out what I'm missing, go build that, and repeat.