In addition to getting her MBA, entrepreneur Steph Korey got a different kind of education by working for two different start-ups, Warby Parker and Casper, and co-founding her own, the luggage company Away.
She calls it "start-up grad school," and it's been even more useful than getting her degree from Columbia Business School.
To be clear, "each one was helpful in different ways," Korey tells CNBC Make It. But "if I had to pick between the two, you always learn more from on-the-job experience."
When you're at a start-up, "you see things like, this is how we scale our operations, this is how we do marketing in a way that resonates, this is how we on-board people, this is how we create a cohesive vision for our team," says Korey. "Those types of things are theories you can learn in a formal education environment, but it doesn't compare to being able to learn on the job."
In early 2015, when Korey had recently graduated from Columbia Business School and was doing part-time consulting work for the online mattress start-up Casper, she got a call from her friend and former co-worker Jen Rubio.