Developing CPS means uniting multiple engineering disciplines: mechanical, electrical and software engineering. Each of them provides a set of models, guidelines and processes crucial for a projects success. Consequently, CPS development is heavily influenced by processes known in either engineering discipline. There is currently no coherent software engineering approach to develop CPS, making it very hard to align the aforementioned domain experts in a controlled and repeatable process. This paper takes a step towards filling this gap by providing the insights during the development of a CPS in the form of an experience report. Based on our findings we validated the use of the Double TwinPeaks model and contribute to the field of software engineering for CPS the Matrix of Granularity to assess the components of a CPS in terms of customizability, risk and constraints.