Alexander Jost received his first musical training with the Vienna Boys' Choir. While studying at the Vienna Music High School, he also studied piano at the Prayner Conservatory under Prof. Stalze. He acquired his choral conducting skills under Univ.-Prof. Herbert Böck. As a singer, Jost has performed in numerous choirs and also worked for six years at the Music Institute for Objectified Music Education. Since 2012, Jost has been working as a répétiteur at the Elfriede Ott Drama Academy and regularly as a musician for the Empire Studio. Alexander Jost conducts several choirs in Vienna and the Weinviertel region, and in autumn 2017 he took over the leadership of the newly founded Karlsknaben choir. Since autumn 2013, Jost has been the elementary school bandmaster for the Vienna Boys' Choir.
As a composer, he has created small choral works, primarily for the Chorus Viennensis. He has also worked for the choir as a singer, répétiteur, arranger and assistant to his predecessors.