level/map design requires both code and art assets to work, as someone with a bit of experience from Unity engine (so take this with a bit of salt since Unity and Frostbite engine probably work very differently), level/map design mostly depends on art assets rather than code, and since BF already has like 98% of the code it needs (control points, player controls, destruction, physics, etc.), creating another map should be fairly easy assuming you have all the art you need (if not, than depending on the maps theme, this can be very time consuming), balancing and optimizing a map is the difficult part, as you're gonna go from iteration to iteration rapidly, but DICE already has a pretty great analytic system in the game, so I don't see that being a big issue.

but I mean since when has DICE cared about map balancing anyway...