He began his 42-year tenure at Renault as a Tool Setter. In 1934, Bézier became Tool Designer and in 1945 became Head of the Tool Design Office. As Director of Production Engineering in 1949, he designed the "transfer machines" that produced most of the mechanical parts for the Renault 4CV. The transfer machines were high-performance work tools designed to machine engine blocks. While imprisoned during WWII, Bézier developed and improved on the "automatic machine principle" introduced before the war by General Motors. The new "transfer station", with multiple workstations and electromagnetic heads (antecedents to robots), enabled different operations on a single part to be consecutively performed by transferring the part from one station to another.