Jsonnet is a tool that allows you to write Json files easily, handle repetitions, data, etc.

Terraform is a tool that works with may API's to create/update/delete objects from a codebase. It is mainly known in the cloud area but has support for grafana too.

Combining those two solutions allows you to write many dashboards in no time - in a reproducible way. And even to create basebricks for multiple dashboards and reuse them at will.