This former couple says splitting up saved their pizza company. Here's why they and others found running a business with your ex doesn't have to be a nightmare.

• Working together after a break-up can be surprisingly successful, couples told Insider.
• For one pair who run a pizza business, getting divorced was the key to thriving professionally.
• For another, selling coffee helped rekindle their failed romance.

Cheese shortages might have been the final straw for Alex Wagner and Arwen Chen's marriage.