He is the chief executive officer and co-founder of Union Kitchen, an accelerator of food businesses.

[3] After graduating, he began his career as an intern in finance before switching to food business.

In 2012, Cullen and Jonas Singer co-founded a pop up coffee shop called Blind Dog Cafe on Florida Avenue.

[7][8] In 2023, he was a speaker at the Good Business Summit[9] and was part of Entrepreneurs in Residence 2023 held by Pillsbury Institute for Hospitality Entrepreneurship.

The accelerator is built out into four phases; Launch, Product Market Fit, Growth, and Scale.