Read "Traction" by Gino Wickman.

You're an integrator. Your co-founder is either a visionary, or he's lazy, or maybe both. I don't have enough info to know for sure.

At any rate, each of you handling separate sides of what is basically two different businesses is a mistake. Sure it does a nice job in giving each of you autonomy, but it's terrible for maximizing each of your unique skill sets.