Maybe you already use configuration management and monitoring but do you test your infrastructure? In this talk you'll see how to create a fully tested Chef cookbook that installs Varnish for caching our website. We'll test our Varnish cookbook with Chefspec, Test Kitchen, Serverspec and create Cucumber tests to ensure our advanced Varnish configuration and website are behaving as we expect. We'll also show how to do the same for other tools such as Puppet, Ansible, AWS CloudFormation etc.