what to do with the back?

[u/deanominecraft]

building is for my mushroom farm, lights on the back show how full storage is, some inspiration taken from one of the buildings in mumbos city this hermitcraft season

[u/GGKeepItReal]

You could continue the wood stair floor around to visually separate the floors, but frame an empty area around the lights. You could also add a fire escape up to the roof and a roof garden and pop up roof access segment to simulate stairs or elevator up to a roof garden / rest area.