Stages of building the messaging app can be broken down to taking the following steps:  Discovery stage UX/UI design Development Launching and maintenance.  At the discovery stage, the deep-scaled business analysis is performed. It implies:  Defining the business and project goals  Defining and portraying the target audience Panning and research Designing the chat app, you need to take into consideration two major factors:  Defining the means of creating ‘visually smart’ interface  Focusing on app responsiveness as the core design characteristics.  At the development stage, the expert team takes the following steps to perform software architecture building: Planning, scheduling and prioritizing the development goals Agile development QA and testing Retrospective.