This article presents a qualitative case study of a Scratch-based simulation project created by a primary school student during a period of remote learning. The study explores how designing a simple agent-based model in a visual programming environment can support the development of digital and computational competences. The analysis draws on three sources of data: the Scratch artefact, competition documentation, and a retrospective semi-structured interview with the project’s author. The findings indicate that constructing the simulation helped the student develop key computational practices – such as decomposition, iterative refinement, and problem-solving – and enabled her to explore causal relationships within a simplified model. The project demonstrates how accessible programming environments can facilitate constructionist learning by engaging learners in designing and testing executable artefacts. The results further suggest that simulation-based projects can enrich remote and hybrid education by providing opportunities for active experimentation and reflective analysis. The study’s main limitation is its single-case design, which narrows the scope for generalisation. Further comparative and longitudinal research is needed to assess wider educational impact of student-created simulations.