I'm an undergrad trying to figure out what career I want to pursue. I consider myself very good at math and physics and enjoy them, however I know that I definitely do not want to go into purely theoretical physics. I have been thinking about what I want to do for a while now and it occurred to me that simulations of high level math/physics may be a good fit. However, I still enjoy building/tinkering with stuff. Hence I am wondering if anyone knows of careers that involve both doing simulations and designing stuff. My initial thoughts were particle accelerators and fission reactors. However I am not sure of the extent to which the simulations folks in these fields actually get to help design stuff (i.e. do they get stuck doing nothing except programming?). Does anyone have any insight? Also if anyone simulations people from different fields are here feel free to comment.