title: Calling an external API whenever a field in the database is updated
body: <p>My <code>ApplicationUser</code> model contains a property:</p>
  
  <pre><code>public bool SubscribedToNewsletter { get;set; }
  </code></pre>
  
  <p>I would like to make sure that whenever I update its value in the database, an external API will be called to add or remove the user from a list in my email automation system, without manually calling the method myself to ensure synchronization regardless of programmer's intention. </p>
  
  <p>Is there a built-in functionality provided in ASP.NET? Or do I have to extend the <code>UserManager</code> class and centralize all the calls updating the database?</p>