Summary: Domain-specific languages (DSL) are specialized modeling languages targeting a narrow domain. In this paper, we present the results of a research project on visual DSLs set in an industrial context, using the domain of elevator controllers. After domain analysis and inception of new, abstract modeling concepts a language prototype was developed, considering aspects such as usability, combination of visual and textual DSLs, and performance of generated code. We describe the challenges encountered during the project, such as defining a user-friendly concrete syntax or tool limitations, and analyze them in retrospective. The paper concludes with several metrics to support the findings.