We’re living in an era without the need to SSH into servers.

Today, modern infrastructure is created from immutable images. Any upgrade is performed by building new images and performing rolling updates that will replace VMs one by one. Infrastructure dependencies are never changed at runtime. Tools like Packer, Terraform, CloudFormation, and the like are the answer to today’s problems.

One of the inherent benefits behind immutability is a clear division between infrastructure and deployments. Until not long ago, the two meshed together into an inseparable process. With infrastructure becoming a service, deployment processes can be clearly separated, thus allowing different teams, individuals, and expertise to take control.