title: Application startup code in ASP.NET Core
body: <p>Reading over the <a href="https://docs.asp.net/en/latest/fundamentals/startup.html" rel="noreferrer">documentation for ASP.NET Core</a>, there are two methods singled out for Startup:  Configure and ConfigureServices.</p>
  
  <p>Neither of these seemed like a good place to put custom code that I would like to run at startup.  Perhaps I want to add a custom field to my DB if it doesn't exist, check for a specific file, seed some data into my database, etc.   Code that I want to run once, just at app start.</p>
  
  <p>Is there a preferred/recommended approach for going about doing this?</p>