How to attend experiential values of a design throughout the implementation is still an open issue. The interplay between experience design and software engineering is problematic because of the different epistemologies of design and engineering. Interaction design is a design practice, whereas software engineering describes itself as engineering and science. There is a long tradition in design of discussing materials and the craft of making artefacts. Thus, if we have a material, it is reasonable to say that we have a craft. If programming language code is a design material, then, making a finished artefact is the shaping of material. The development process can thus continue as a design process up to version 1.0. This paper presents a design case up to version 1.0 of a music creativity app, utilising design through programming. The app design validity was evaluated in a field study at an electronica music festival. Material consciousness of code, and an open-ended, and quality-driven design process allow attention to the experiential qualities of the design.