This paper critiques the concept of 'professional trajectory' as in, for example, organizational theory where it is discussed in terms of career advancement and patterns of internal mobility (Sullivan 1999).The work on 'boundaryless careers' (Rousseau & Arthur 1996) replaces linear by 'protean' models where the practitioner is thrown back on her self as a designer of her own learning process - a disembedded self (Beck 1992). Wenger & Snyder (2000) see the learning process as a gradual transition into a community of practice, informally bound by shared expertise and passion for a joint enterprise. Dreier (1999) distinguishes between personal trajectories and institutional as the space that professionals appropriate. In cultural historical activity theory Beach (2000) reformulates knowledge transfer as consequential transition that changes the relationship between the professional and social activities. We use the concept of "epistemic trajectories" to represent knowledge as an unfolding process (Knorr Cetina & Bruegger 2002) that is intrinsically motivating for expert groups in post-social cultures and consider a universe of knowledge that may be taken as "objective" in a Durkheimian sense (Young 2002). Based on this framework, a longitudinal study is being conducted of graduating students in nursing, teaching, engineering and accounting through their first years at work using research instruments that are sensitive to both time-space compression and distantiation of learning processes.