This article is a didactic contribution to the subject area known as “technology comprehension” in Danish K-9 schools. In this context, technology comprehension is regarded as a discipline that involves developing competences in the fields of computational thinking, design thinking, and critical thinking regarding the use of computer science in society. The article communicates the results of an experiment conducted in a Danish eighth-grade class. The purpose was to examine a way of teaching computational thinking and design thinking by developing a computational design to solve an authentic problem, thereby identifying didactic opportunities and challenges. The experiment was based on two primary hypotheses: We expected the students would dislike the idea of changing their designs after user feedback, and we thought they would have a narrow view of computer science, regarding it as the equivalent of programming. These hypotheses were partially confirmed. However, other opportunities and challenges were also identified, including changed conceptions of computer science and new opportunities for success within the field, success with creative breaks and varied ways of working, the positive importance of authenticity with regard to the students’ understanding, and the wish for a greater degree of freedom than they were granted in this project.