This talk was presented at App Design & Development Conference in Barcelona, 2017 -- The journey from a basic idea to a great product requires clear communication and close collaboration between design and development teams. In this talk we are discussing why and how engineers should be a part of the design process, how to create shared understanding and how to build a better design and development culture. This is a story from a designer and a developer who worked together and built a product for people who really need it. It is a first-hand story about behind-the-scenes processes, results, and reflections about the design & development of a medical app which actually saves people’s lives. We will walk you through our design process from ideation and brainstorming, research and user study to first prototype and iterations. We will talk about why and how engineers should be a part of this journey, how to create shared understanding about users, and how to create a product that makes someone's life better together. Is it all about pixels, colors, lines of code, or is it about users?