After graduating from the Culinary Institute of America, Carmen became an apprentice at the Greenbrier Hotel in West Virginia under Chef Hartmut Handke. Three years later, he headed west to work for Michael Chiarello at Tra Vigne in Napa Valley. There he quickly advanced from Sous Chef to Executive Sous Chef to Executive Chef/Partner.
In 2001, Carmen was hired to work for Lydia Bastianich at Felidia in New York City. He then moved to Boston and became Chef at The Vault, which quickly earned three stars from both the Boston Herald and Boston Globe. A few years later, Carmen moved to New York and assumed the role of Chef de Cuisine at Union Square Cafe, working under Chef Michael Romano. He was promoted to Executive Chef in September 2007, where he has remained at the helm, eventually transitioning the restaurant from its original home on 16th Street to its new location on 19th Street in 2016.