This document summarizes a presentation about scaling out SignalR applications. SignalR allows real-time web functionality by pushing messages to clients using techniques like websockets. To scale SignalR, developers must understand how to distribute hub instances across servers and measure traffic patterns. The presentation covered best practices like using groups and async calls. It also described pluggable backends like SQL Server and Redis that can be used to share state across servers. Finally, it gave examples of custom scale-out scenarios using techniques like server transitions and filtered message buses.