While still in school, Scarlett worked as a design assistant and patternmaker on various projects ranging from opera to dance, film, and on Broadway.

Scarlett found success on the first season of the Bravo reality show Project Runway in 2004-2005, though was eliminated in the penultimate challenge.

During the airing of Project Runway, he became known for his ability to produce glamorous fashions under the tight deadlines and unusual requirements of the competitive reality show.

In January 2006, he joined New York–based bridal-design house Amsale as Creative Director of its luxury gown collection, Kenneth Pool, where he served until 2009.

The series premiered July 29, 2010, on the Lifetime network, and followed the pair cross country as they created couture designs using local resources.