This article explores how experts from the European Union and Georgia interact within the framework of Twinning projects, a key instrument for implementing EU legislation in partner countries. Drawing on 39 qualitative interviews across 12 projects conducted between 2012 and 2020, the study applies Maia K. Cross’s framework on epistemic com-munities to assess the effectiveness of expert socialization. This article reveals that informal interactions, shared professional norms, and common post-socialist experiences signifi-cantly enhance collaboration and policy implementation. Conversely, prior professional ties and group innovation were less influential. The article argues for a revised understanding of socialization dynamics in EU external governance, emphasizing the importance of informal settings and cultural proximity. These insights contribute to broader debates on norm diffu-sion and institutional capacity-building in the EU’s Eastern Neighbourhood.