From 1958 to 1964, worked as a designer in the studio of designer Victor Gruen. He also worked in the studio Daniel Johnson Medehal Los Angeles, the United States. After the tragic events of the 1963 earthquake, Konstantinov returned to Skopje to help rebuild the city. His Telecommunications Centre and Post Office (built in different stages between 1974 and 1989) are two of his most recognizable contributions to the rebuild of Skopje.