Undergraduates in Spanish universities conclude their Bachelor of Science in Telecommunication Engineering with a capstone project. In recent years, students in technical degrees often postpone this last step due to an accelerated entry into the labour market or disappointment about the capstone project development. This article presents an approach which attempts to overcome these challenges: \textit{Engagement} capstone projects. The authors, lecturers in two Spanish Universities (Universidad Politécnica de Madrid and Universidad Rey Juan Carlos, supported by the French Company, EOMYS, manage this educational project. Students become responsible for their contribution to a free, libre and open software project, which provides sound quality metrics based on psychoacoustics. They have the opportunity to work in a collaborative and international environment with industrial partners. The presentation of the technological platform shows the educational benefits of the employed tools: Python, GitHub and Jupyter Notebook. A student survey and the supervisors feedback supports an analysis, which helps improve the methodology as well as verify the benefits: better supervision, the development of social and professional skills, and useful community work. Finally, a couple of examples of Engagement capstone projects give insight into the results of this educational strategy.