API updates should be rolled out with an opt-in and out option. So that developers can test and adopt new versions and roll back if problems occur. Currently we just get a new version and if this new version breaks any of our custom integrations. We have no way to compare to old behaviour or opt out of the update until we can fix this.
Example of this is the November API changes. The change broke how some of our APIs customizations worked. Our ICT developer team had to make changes to resolve the problems that the November API change made. Then 2 months later Ex libris changed the API to resolve the bug that November had made. This update broke the workarounds that our developers have created. So our ICT developers have then had to work on a second resolution within a very short space of time. This is specifically problematic for our ICT developers as the issue is system critical and therefore needs to be done quickly. Whereas versioning API changes would resolve this.