...

X-Okapi-Url and X-Okapi-Tenant headers could be set from the request to the Kafka message.

RA: I'm also thinking about versioning of such schema, just to cover potential extension in it and avoid version compatibility issues.

Domain events for delete all APIs

...

{ "type": "DELETE_ALL", "tenant": "<the tenant name>" }

Other items and aspects

Event schema versioning

Q: Does it make sense to include explicit version field into domain event schemas?

A: Potentially, this would make sense. Though now the basic schema is extremely straightforward so that there's a very small chance for changes. Also, adding new fields later should not be a breaking change.

Retention policy

Q: Retention policy recommendations - should particular cross-platform standard for that be recommended?

...