In this presentation, we introduce a concept for promoting students epistemic agency in the context of data-driven, real-world problem-solving activities. Students develop so-called computational essays as products of their modeling and programming processes, which are intended to make the solution to the problem and the process comprehensible and reproducible. In this article, we report on the first implementation of this concept as part of the modeling week of the CAMMP student program as well as initial findings from the pilot study.