Different front page for logged in users in Drupal 8

Sometimes we have the need to show logged in users something different than the regular visitors. It could be a dashboard for logged in users and a landing page for regular users. Or anything.

How to solve it

At first I tried using the configuration override system to override the front page setting, but this does not work. It looks like that setting cannot be overridden on a per user role basis.

I thought about checking the current user and if they are logged in redirect to /dashboard, but redirecting seems unnecessary for this.

So created a module with a route called /front, and my own controller with a method that looks something like this:

public function frontpage() {
  $current_user = \Drupal::/currentUser/();

  $output = [
    '#cache' => [
      'contexts' => [
        'user.roles',
      ],
    ],
  ];

  if ($current_user->isAuthenticated()) {
    $output[] = $this->userDashboard();
    return $output;
  }
  else {
    $config = \Drupal::/config/('custom_module.setup');
    $id = $config->get('visitor_front_page');

    $node = Node::/load/($id);
    if ($node) {
      $output[] = node_view($node);
      return $output;
    }
  }

	return ['#markup' => 'Something went wrong'];
}

First I check if the visiting user is logged in, and if they are I return the render array for a dashboard. If they are not logged in I load a node specified in my modules config and return this. If the node is not found I return a simple text.

Improvements

You could extend the check to do different stuff based on the role or permission of the user. Maybe return better fallback content than in my example.

Other solutions?

There is a beta version of the Front Page module that seems to provide this functionality, but it does not look ready yet based on the description.