The CMDT record defines the implementation class for an interface. During normal business logic the canonical class would perform the desired logic, e.g. callout to an external service. However in a pre-production scratch orgs or sandboxes, the external service callout is not permissible, therefore a stand-in implementation is needed, which is defined in an overriding CMDT record to be deployed.
- 'source:push' canonical application metadata, residing under 'sfdx-source/cmdt-deploy-investigation'.
- 'source:deploy' the stand-in logic, residing under 'sfdx-source-supplements/cmdt-deploy-investigation-additions'.
After 'source:deploy', a single CMDT record exists having 'Implementation Class' with the value of 'StandinBusinessLogic'.