title: Using system.text.json with Azure Functions
body: <p>I am trying to find good code examples of using System.Text.Json with Azure Functions</p>
  <p>I understand it's still a fairly new package but it's performance benefits are compelling, what I can't find is a simple example to import it in an Azure Function and do a basic JSON serialise and deserialise call.</p>
  <p>E.g for a httpclient postasync call using Functions v4</p>