For me, and many others: infrastructure as code.

Kubernetes is very complex and took a long time to learn properly. And there have been fires among the way. I plan to write extensively on my blog about it.

But at the end of the day: having my entire application stack as YAML files, fully reproducible [1] is invaluable. Even cron jobs.

Note: I don't use micro services, service meshes, or any fancy stuff. Just a plain ol' Django monolith.

Maybe there's room for a simpler IAC solution out there. Swarm looked promising then fizzled. But right now the leader is k8s[2] and for that alone it's worth it.

[1] Combined with Terraform

[2] There are other proprietary solutions. But k8s is vendor agnostic. I can and have repointed my entire infrastructure with minimal fuss.

Do you have a recommended tutorial for engineer with backend background to setup a simple k8 infra in ec2?

That’d be a great first step if the purpose is to learn Kubernetes. If, however, you want to set up a cluster for real use then you will need much more than bare bones Kubernetes (something that solves networking, monitoring, logging, security, backups and more) so consider using a distribution or a managed cloud service instead.