You are developing an application that applies a set of governance policies for internal and external services, as well as for applications. You develop a stateful ASP.NET Core 2.1 web application named `PolicyApp` and deploy it to an Azure App Service Web App. The `PolicyApp` reacts to events from Azure Event Grid and performs policy actions based on those events. You have the following requirements: Authentication events must be used to monitor users when they sign in and sign out. All authentication events must be processed by `PolicyApp`. Sign outs must be processed as fast as possible. What should you do?