Do we need to upgrade DataStage or MettleCI because one or the other has been an upgraded?
No. MettleCI will always be backwards compatible with DataStage v8.5+, and is compatible with new DataStage releases within a week of their release by IBM. You can upgrade DataStage or MettleCI independently of one another. This is, of course, assuming IBM don't immediately deprecate or radically alter any of the standard interfaces that MettleCI uses to deliver its functionality. Given our strong relationship with IBM's development team this is unlikely to happen without our prior knowledge.