--- - |2 Ecological approaches to professional work, authority, and regulation have seen a resurgence in the sociology of professions, as epitomized in the linked ecologies framework of Andrew Abbott. Alongside this resurgence comes a renewed attention to the way symbolic and material boundaries within and between professions, as well as between professional, university, and political institutions, come to be defined, negotiated, and changed as part of ongoing professional projects. Building on and comparing case studies set in Denmark into three emerging professional “proto‐jurisdictions”—of water‐related climate adaptation, lifestyle disease prevention, and innovation management—this article identifies three key modes of interprofessional boundary work important for such projects. In doing so, it grounds Abbott's meso‐level framework of linked ecologies in more situated accounts of workplace‐level boundary interaction, by reconnecting to a wider tradition of symbolic interactionist studies of professions. - 'Symbolic Interaction, EarlyView. '