At Netflix, an increasing percentage of the millions of devices that use our service are mobile devices. The usage of these low-end mobile devices with small screens and reduced computing power to access Netflix fact has led to a paradigm shift on the User Interface team such that being mobile first is one of our top priorities. Being mobile first means that minimum performance and design specifications are applied to the most common low-end devices so that every user receives the optimal Netflix experience. This talk will break down what it means to be mobile first and how this new strategy impacts everything from the product design to architecture decisions.