[5] He worked on the styling and design of the Polo Ralph Lauren flagship store, the former Rhinelander Mansion, on Madison Avenue in Manhattan.
[13] O'Brien is a prolific product designer who has developed a portfolio of high-end home furnishings with a number of American heritage brands.
[20] In 2000, he launched the largest-ever designer collection of furniture, lighting, and soft home furnishings with retailer Target.
[21] Through Aero Studios, O'Brien focuses on the design of private residences as well store development for retail brands.
[12] In addition, O'Brien has collaborated with Williams-Sonoma, Inc., for whom he designed store concepts for West Elm[23] and Pottery Barn.