You need to add one field to an event and remove another, and five teams consume it. How does that roll out?

Short answer

Additive changes with defaults are safe, removals are not, so split every removal into deprecate-then-delete with evidence that nobody reads the field. Register the schema, pick a compatibility mode deliberately, and note that backward compatibility requires consumers to deploy first.

This is event driven schema evolution. Good event driven design assumes old and new consumers coexist, so schema evolution must be additive, versioned, observable, and reversible. Weak schema evolution breaks consumers by reusing a field name or changing meaning in place. Strong event driven systems treat schema evolution as a compatibility contract across teams.

Event driven ownership means every producer treats compatibility as part of the release.