In 1923 Jost was invited by Georg Hartmann[2] to become the art director of the Bauer Type Foundry in Frankfurt am Main.[1] He directed Bauer during its most successful period, until 1948.[3] At Bauer, he oversaw the work of designers such as Paul Renner, Lucian Bernhard and Imre Reiner [de].[4] Jost personally designed several typefaces for Bauer: Atrax (1926), Bauer Bodoni (1926), and Beton (c. 1931–1936). He also designed Jost Mediaeval for Ludwig & Mayer (1927–1929) and a revival of Fraktur for Monotype (1938).[2] Beton was popular among advertisers, while Bauer Bodoni, which was created as a rival to Morris Fuller Benton's ATF Bodoni, is generally regarded by typographers as the most faithful revival of Giambattista Bodoni's original typeface.[2][3] His other designs include Aeterna (1927) and Georg Hartmann Antiqua (1948).[3]