Learn to automate your infrastructure with Terraform and Terragrunt in a modularized way. Declare your servers as cattle and don't manage them like pets. That's what you are able with fully automated infrastructure.
Terraform modules help you to decouple your infrastructure into reusable components and code them together in a flexible way. With Terragrunt you are able to organize and evolve your infrastructure in a versioned and structured way. With both tools together you have whole insight into your infrastructure by just looking at the code.