Application developers play a key role in organizational security. Gone are the days when an application and its developers can assume that the network perimeter is secure. With work originating from anywhere on any device, applications need to be developed in a way that incorporates Zero Trust principles throughout the development cycle. A compromised application today can have an impact on the entire organization. Developing apps that incorporate the Zero Trust framework will increase security, reduce the blast radius of a security incident and help recover swiftly. This whitepaper first covers the Zero Trust model and how it impacts the work developers do. Then, it provides Zero Trust best practices that developers can follow when developing with the Microsoft identity platform.