Deploying Drupal behind an AWS Elastic Load Balancer in combination with Cloudfront is really not an easy task. Because all of a sudden your website gets fast, but if you want to log in as user, you get a 403. First I thought that would be something I have to accept when using Cloudfront. But Cloudfront even forwards Cookies and other stuff. That way the caching is not as good as before, but the website behaves as if it would be hosted on one simple server. Only with the positive impact that it is much faster in many parts of the world.