When it comes to XML Schema, nothing is easy. But Eric van der Vlist's book "XML Schema" helps clear up some of the complexity.

Fauna’s new declarative schema language enables a ‘Schema-as-Code’ approach which means that developers can fully automate changes within existing CI/CD workflows by applying IaC-like design ...

Ariga, an early-stage startup, wants to help by letting users define database schema as code, and greatly simplify how they interact and manage databases over time.