National audience The transmission of professional knowledge in a working situation has become a key public policy challenge in recent years. But do we see all the dimensions? It is often seen as playing only in the meeting of two individuals, an old and a young person, and aimed at the transfer, in a one-way sense, of specific knowledge within that couple. This knowledge of employment suggests a different approach to the transfer of knowledge in the professional world. The analysis it proposes, based on field research, aims to capture the process in a broader sense. The aim here is to shift the eye to this process in terms of collective, interactive and multidimensional activity. It is an invitation to broaden the debate on transmission, in particular in negotiations between the social partners, in the design of public schemes aimed at promoting it, or in its implementation within businesses.