Sure it's not for everyone. I learnt a lot doing cash strapped startups where there wasn't a devops person. AWS can get expensive, especially when you start using more and more services (lambda,dynamodb,rds,elasticache etc) although it can be easily scaled.
Note, you probably shouldn't do it by hand (setting up your own servers). You'd use Ansible/Terraform.
For those that are interested but not quite ready, here's a great article [0].
A good example of ASCII diagrams: https://github.com/fpereiro/backendlore
I have found this to be useful: https://github.com/fpereiro/backendlore
It is more about writing backends generally, but in it he uses Redis as a primary database and walks through durability and scalability.
Was it "How I write backends" [1] (previously posted to HN [2])?
As a less experienced web developer, i found "How I write backends"[1] very enlightening and I recommend it to all my peers when we discuss useful resources.