ABSTRACT This article examines the extent to which the increasing ethnic diversity of Northern Europe’s population translates into exposure between natives and migrants (and their descendants) in the workplace, using Danish register data over nearly three decades. Consistent with the expectations of neo-assimilation theory, we find that Danish workplaces have become a common site of mutual exposure, including exposure between natives and two subcategories of culturally distant migrants. At the same time, consistent with segmented assimilation theory, we find increasing segmentation, even in a highly regulated Danish labour market. The distribution of migrants and their descendants in workplaces increasingly deviates from a (simulated) random distribution and we find increasing discrepancies between opportunity pools and exposure levels, particularly at the lower end of the labour market. By opening the black box of workplace composition, this article demonstrates the co-occurrence of increased exposure and labour market segmentation, with its potential to respectively facilitate and hinder integration.