Valdes moved to Miami at age 5 from Colombia, then moved again at age 12 to Marietta, Georgia. He studied at the University of Michigan with the actors of the theater group StarKid Productions. In 2011, after graduating, Valdes was devoted entirely to the theater.Between 2009 and 2011, he participated in theatrical productions of High School Musical and The Wedding Singer before starring in the national tour of Jersey Boys.From March 2013 to March 2014, he played the role of Andrej in the musical Once, in which he also performed on piano, guitar, ukulele, bass and percussion. In 2013, the musical was nominated for a Tony Award.In 2014, Valdes made his television debut in the American series Arrow, before appearing in the spin-off series, The Flash, as a series regular in the role of Francisco "Cisco" Ramón, an engineering genius. Cisco is part of the S.T.A.R. Labs team, along with Dr. Harrison Wells and Caitlin Snow, that help Barry Allen with his superpowers.