Often, vocational education and training (VET) professionals are not systematically prepared for their demanding, mostly diverse and complex tasks. Professional development can be understood as an enlargement of competencies that arise as opportunities in daily work. This study, embedded in a funded research project, focuses on VET professionals and their professional development. The research question is as follows: What challenges and problems regarding their professional development, as well as possible solutions, are described by training professionals in VET in Germany?