This paper explores the concept of apprenticeship in the context of the professional formation of knowledge workers. It draws on evidence from research conducted in two knowledge intensive organizations: a research-intensive, elite university; and a "cutting edge" software engineering company. In the former, we investigated the learning environments of contract researchers, whilst in the latter, we focused on the learning environments of software engineers. Both organisations have "global" reach in that they operate within international marketplaces and see themselves as international players. The paper asks to what extent the important role of maturation with regard to the formation of expertise is being undermined by the pressurised nature of contemporary workplaces (in both the public and private sectors). It argues that conceiving the professional formation of knowledge workers as apprenticeship provides a way forward to improve the way employers construct and support that formation.