In accordance with one disclosed method, a first computing system may receive a message from an application hosted on a second computing system, the message being indicative of an event of the application. In response to receiving the message, the first computing system may generate a notification indicative of the event and send the generated notification to a client device. The first computing system may receive a response to the notification from the client device, and may process the response so as to cause the application to take an action responsive to the event.