Job profiles in German adult education are manifold, and the requirements for engaging in professional activity are only minimally regulated by the state. It is primarily the providers in adult education who decide on access to the professional field and influence the historical development of job profiles. The article presents findings from a historical longitudinal analysis of job advertisements and other historical documents, focusing on the historical genesis of job profiles in adult education in the Federal Republic of Germany. The analysis draws on theoretical concepts from "Economics of Convention" (EC) research on occupational categories, intermediaries, and labor markets. The results demonstrate that the conception, dissemination, and long-term establishment of a specific job profile for adult education were only made possible through the interaction of different actors, each taking on different intermediary functions.