Design is good(be it art, map design, graphical user interface, maybe even something technical like how monsters behavior or sound design) but your initial design is bound to change. What you initially plan might be different from the final product.
You really need the prototype of the game to be up and running to get a sense of what not only looks good but also plays well. If the controls and user experience don't match, it can hurt the game. Having a prototype also tells you what is technically possible and not depending on what technology you are working with.
With some game companies closing down, I'm sure there will a software engineer looking for this position.
Good luck with the prototype!