We study project-based, technology-enhanced learning environments in higher education, which should produce, by means of specific mechanisms, learning outcomes in terms of transferable knowledge and learning-, thinking-, collaboration- and regulation-skills. Our focus is on the role of objects from professional practice serving as boundary objects and the authentic mechanisms they are to activate. We identify three sets of features of boundary objects: (1) facilitation of the interaction between actors enacting various roles; (2) handling in diverse physical and digital spaces; and (3) usage across certain timeframes. Data from an in-depth case study show that these features help to activate authentic mechanisms, namely, using expert performances, enacting multiple roles and perspectives, collaboratively constructing knowledge, reflecting and articulating. The identification of boundary objects and the way they trigger authentic mechanisms for learning, provide concrete guidance for the design of project-based, technology-enhanced learning environments in higher education. (Contains 3 tables, 9 figures and 2 notes.)