http://blog.codeship.com/immutable-infrastructure/
blog-post-codeship-immutable-infrastructure#more-complex-than-necessary1 "You can still use Chef, Puppet, CFEngine or Ansible to build your images, but as they aren't built for an immutable infrastructure workflow they tend to be more complex than necessary." blog-post-codeship-immutable-infrastructure#more-complex-than-necessary1
blog-post-codeship-immutable-infrastructure#rollback1 "Data schema changes are a potential problem, but that's a general issue with rollbacks. Backwards compatibility and zero downtime deployments are a way to make sure this will work regardless of the changes." blog-post-codeship-immutable-infrastructure#rollback1