Prior to transferring to NY in 2008, Guillermo was appointed General Creative Director of Y&R Argentina in 2004. Under his creative leadership, the office was honored as a Top 10 Agency in the 2006 Gunn Report. In 2007 Guillermo added Regional Creative Director to his responsibilities, overseeing the creative product for all of Latin America.

He now represents the region from Y&R global headquarters in New York, where he also serves as Creative Director on global brands like Dell, Virgin and Bacardi. Guillermo has won hundreds of national and international awards at the most prestigious advertising festivals. He has participated as jury member at award shows including Cannes, D&AD, Clios, FIAP, New York Festivals, El Ojo de Iberoamérica and El Sol.