REST is a lightweight architecture for building client-server applications. It uses standard HTTP methods to allow requesting and modifying resource state representations. While SOAP and web services will continue to be used, REST is better suited for mobile and web applications. Organizations are realizing they cannot replace existing technologies and instead focus on integrating technologies to leverage their respective strengths. Exposing existing systems through a REST API gateway allows for coexistence while providing a clean interface. Security, caching, throttling and monitoring are important when managing REST APIs at an enterprise scale.