The technology relates to executing a multi-portion web application. A web browser executing on one or more computing devices may load a main portion of a web application into a main window. The web browser may load into a sandboxed environment a feature application. The feature application may include a portion of the web application. A release isolation framework (RIF) executing on the one or more computing devices, may apply one or more patches to the sandboxed environment. The one or more patches may be configured to redirect elements from a window of the sandboxed environment to the main window.