title: Run custom code on startup of a Remix web application
body: <p>In a Remix Web application, how can we run custom code on startup?</p>
  <p>For example, I want to initialize a database connection pool and run a dummy query to check for problems after the application starts. I know I could do that the first time I use the database, but that's not exactly what I want.</p>
  <p>I'm using <em>Remix App Server</em> as deployment target.</p>