He has walked in shows for Salvatore Ferragamo, Roberto Cavalli, Tommy Hilfiger, Emporio Armani, Viktor & Rolf, Lacoste, Dsquared2, Narciso Rodriguez and Michael Kors and appeared in Vogue, Details, Numéro, V Man and L'Officiel Hommes. Nessman is currently the third most successful male model in the world behind Baptiste Giabiconi and Sean O'Pry on models.com list of the Top 50 international male models, as of December 2010. He is of half Austrian and half Scottish descent. His hobbies include watching Seinfeld, playing basketball, camping and surfing.