10.35Event schema versioning

Events themselves are contracts.

Today:

{
  "customerId": "C001",
  "status": "ACTIVE"
}

Tomorrow someone adds:

{
  "customerId": "C001",
  "status": "ACTIVE",
  "region": "US"
}

Usually additive change is easier.

But removing/renaming fields may break consumers.

So treat:

event schema

with the same seriousness as:

REST API schema

This is directly relevant to automated contract testing.