Purpose: to work out a hypothesis for the introduction of a new card service for banks. It was necessary to analyze the entire user path (user flow) from the hypothesis to the real prototype. It was necessary to integrate a hypothesis about a new product on the basis of a real operating application, which was probably the most difficult and interesting, to think through the whole way with all the nuances and options. So we made hints for the user along the way, simulating the first entry into the application and facilitating the understanding of the new functionality.