Hi, author here.
At least from my personal experience, there are still many jobs in which the main focus isn't frontend development, and per se React.
I do have to work with React from time to time. But it isn't my main focus. I usually work implementing backend systems (with Go, SQL [Postgres], Redis, etc.) and infrastructure as code with Terraform.
I do have to work with React from time to time. But it isn't my main focus. I usually work implementing backend systems (with Go, SQL [Postgres], Redis, etc.) and infrastructure as code with Terraform.