API Versioning in RESTful Systems: Lessons from the Field

Versioning is hard. But deprecating unversioned APIs? Even harder.

This quarter, we migrated a set of internal APIs to a versioned model using URI-based versioning (/v1/ style). Key lessons: - Include version negotiation in contract discussions - Avoid URI pollution with semver unless truly needed - Backward compatibility ≠ never change

Relative stability, clear upgrade paths, and automatic contract testing helped streamline our rollout.