I use the AddService() method to inject a things on occasion but its not used heavily. For lightweight apps I'll spin up things like a shared SQLiteConnection and inject it for all resources to use.

The DI pattern is simple & clean at this scale. In my top-level program I define my routes like:

  app.Map("/", Home.HandleRequest);
  app.Map("/login", Login.HandleRequest);
  app.Map("/account/new", NewAccount.HandleRequest);
  app.Map("/{owner}", OwnerHome.HandleRequest);

  static async Task HandleRequest(HttpContext context, SQLiteConnection sql)
  static async Task HandleRequest(HttpContext context, SQLiteConnection sql, string owner)
  etc...