When someone else changes.
WHAT HAPPENS
A provider changes behaviour, and your integration breaks.
WHAT WARNING YOU USUALLY GET
Some. Occasionally none.
WHAT TO DO IN ADVANCE
Subscribe to their changelog and status notifications Record which version you use Monitor for unexpected response shapes
WHAT MONITORING FOR SHAPE MEANS
Alerting when a response fails to match expectations.
WHY THAT IS THE EARLY WARNING
It catches silent changes before users report them.
WHAT TO BUILD
Validation of responses against what you expect.
WHAT TO DO WHEN A CHANGE IS ANNOUNCED
Assess what it affects Schedule the work Test against their new version, if available
WHAT TO DO WHEN A CHANGE ARRIVES UNANNOUNCED
Confirm it is genuinely their change Report it to them Work around it if necessary
WHY REPORTING MATTERS
Unannounced changes are frequently mistakes on their side.
WHAT TO KEEP
The evidence: request, response and time.
WHAT TO AVOID
Building on undocumented behaviour.
WHY
It is not a contract, and it changes without notice.
WHAT TO DO IF YOU MUST
Isolate it, document it, and monitor it specifically.
WHAT TO RECONSIDER
Providers that change repeatedly without notice.
