Appreciated by Polish legendary musicians Czeslaw Niemen and Michał Urbaniak (with whom he collaborated on several occasions). Artistically active outside of Poland having collaborated with U.S. (Marco Polo, Evidence, El da Sensei, Cadillac Dale, Jeru The Damaja, Torae), British (Skill Mega, Dirty Diggers), and Dutch (Joe Kickass, Sacha Vee) artists. Together with Dutch musicians Chris Van Rootselaar and Jaap Wiewel created a producers' collective called Killing Skills. Being a classically trained graduate of Music Academy in Lodz (violin as leading instrument), O.S.T.R. creatively incorporates his academic skills into his music.