Compatibility Philosophy
Favor additive changes; batch removals on predictable schedule. Offer structured deprecation notices.
Versioning Approach
Use resource capability negotiation or explicit version headers vs global monolithic versions.
Change Flags
Provide opt-in flags for clients to test upcoming behavior in production safely.
Deprecation Pipeline
Stages: announce → metrics watch → dual write/translate → sunset date → removal.
Testing & Monitoring
Contract tests for major clients. Metrics: usage by field, error spikes post deploy, flag adoption percent.
Communication
Public changelog, migration guides & automated diff summaries via developer portal.