Due to fast and unpredictable developments, professional education is challenged with being responsive, which demands a rethinking of conventional curriculum development approaches. Yet, literature on curriculum development falls short in terms of recognising how to react rapidly and adequately to these new developments. This study focuses on curriculum development initiatives at the school level in a Dutch university of applied sciences. Open interviews were held with 29 curriculum developers to explore how they define and give substance to developing curricula for new, changing or unpredictable professions. These 29 participants were involved in seven curriculum development trajectories. Four themes were detected: (1) curriculum developers are in favour of open, flexible and authentic curricula; (2) the context in which the curriculum development takes place and the different roles and responsibilities of curriculum developers are challenging; (3) curriculum developers feel insufficiently equipped to carry out their tasks; and (4) involving stakeholders is necessary but results in a "viscous" social-political process. Responsive curriculum development requires a great deal of flexibility and adaptability from curriculum developers. Yet, in our study, "institutional concrete" is found to severely hinder responsive curriculum development processes. To be responsive, such processes need to be supported and institutional barriers need to be removed.