Consider the following scenario. Your company is planning to launch a new website that provides stock price information to customers. Recently, an intern created a website prototype for the new application and the Lead Architect has now asked you to step in and improve the solution.

Your objective is to update the app to implement automatic updates of the stock price information, but ensure communication between the client and server happens only when data changes on the server.

Learning objectives

In this module, you will:

  • Implement a function in Azure Functions that runs only when data changes in an Azure Cosmos DB.
  • Implement a function in Azure Functions to broadcast changes to connected clients using SignalR Service.
  • Update the client web application to respond to SignalR messages.


  • Ability to read JavaScript.
  • Familiarity with Azure Functions, Azure Cosmos DB, Azure Storage, and Visual Studio Code.