This chapter focusses on two challenges for socio-technical design: Having to choose between different rationales for design, and the adequate understanding and depiction of the work to be redesigned. These two challenges betwixt the otherwise strong tenets of socio-technical design of pointing out the intrinsically social and technical interwovenness of design, and the necessity of including affected people and stakeholders in the design process. This betwixtness of socio-technical design is demonstrated by the analysis of two IT systems for healthcare: a foundational model for electronic healthcare records, and an IT system organizing hospital porters’ work. The conceptual background for the analysis of the cases is provided by a short introduction to different rationales for organizational design, and by pointing to the differences between a linear, rationalistic versus an interactional depiction of work.