He is best known for both his art deco illustrated books and iconic turnstile for the Perey company, as well as modern radios, broadcast equipment, and televisions for RCA.

He studied alongside[clarification needed] American artist John Singer Sargent and worked as an assistant for Joseph Urban.

[2] He opened his own studio creating window displays for department stores, like Wanamakers, murals, and advertisements for Saks Fifth Avenue, Bonwit Teller, and Packard Motor Cars in his unique black and white illustrated style.

[4] He entered the emergent field of industrial design and was hired by rapidly-growing RCA Victor, under the leadership of David Sarnoff, who discovered Vassos while painting murals at the WCAU skyscraper in Philadelphia.

[4] Vassos's work as an interior designer included the Chrysler Building apartment of photographer Margaret Bourke-White, Nedick's Hot Dog stands, displays for RCA in department stores and the World's Fair, and many others for which he employed modular furniture.

Between 1927 and 1935, Vassos illustrated many books, including Salome, The Ballad of Reading Gaol, and The Harlot's House and Other Poems – three literary works by Oscar Wilde published by E. P. Dutton.

It was performed as a dance by choreographers Gluck Sandor and Felicia Sorel with sets designed by Vassos and had a limited run of 1,000 books.

[12] Ultimo (1930) presented a dystopic vision of a future underground society using streamlined motifs and was a response to debates about an urban landscape dominated by skyscrapers by writers like Lewis Mumford.

[14] Other notable designs included a streamlined paring knife, Hohner accordions and harmonicas, computers, an electron microscope for the RCA company, corporate logos, and Remington shotguns.

Vassos designed numerous radios, phonograph players, the Constellation jukebox for the Mills Company, and total environments for movie theaters, international expositions, and restaurants.

John Vassos's contributions to public projects, like the famous RCA Building for the 1939/1940 New York World's Fair, have been overlooked for decades.

[16] For the 1939 New York World's Fair he created a novel TV cabinet in transparent Lucite plastic as well as the company's first mass-produced television sets – the TRK12, TRK-9, and TRK-5.

Like many of Vassos' designs of media technologies, they are devoid of direct references to streamlined vehicles and inspired by the spare aesthetics of the Bauhaus School.

[citation needed] John Vassos was a founder of the industrial design profession in the United States and strived for excellence in the field.

Due to his extraordinary leadership, cleverness, unsurpassed skill-set and knowledge of the Mediterranean, as well as his fluency in Greek and Turkish, he was assigned to the 'Secret Intelligence' (SI) and 'Special Operations' branches (SO) of the Office of Strategic Services and promoted to major and put in charge of the secluded ‘Spy School’ in Cairo, Egypt.

[27] This clandestine training center was a Camp X-type facility, situated in a remote, upper-class suburb of Cairo along the Nile River, known as "Area A."

[30] Vassos' detailed drawings, for the OSS training manuals and films, were used by prospective agents and attest to his unique artistic talent.