title: Executing async code after startup, once API is up for requests
body: <p>I'm trying to execute logic on start up of my web API and this code will also be async.</p>
  <p>I've thought of <code>IStartupFilter</code> but this is sync, which is a problem. <code>StartUp.Configure()</code> is also not an option, sync.</p>
  <p>I've thought of <code>IHostedService</code> but this runs before the application is done loading and up for requests.</p>
  <p>Any other ways of doing this ?</p>