Amazon S3 or Amazon Simple Storage Service is a service offered by Amazon Web Services (AWS) that provides object storage through a web service interface.
Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Drupal is a free and open-source web content management framework.
Mailchimp is a marketing automation platform and email marketing service.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Pantheon is a WebOps (Website Operations) and Management Platform for WordPress and Drupal.
Varnish is a reverse caching proxy.