I am using AWS Flow Framework for setting up SWF. SWF recommends bumping up versions of activities or workflows if backward incompatible changes are introduced. Can changing dataconverters be considered a backward incompatible change breaking workflow replay?
Dataconverters: https://docs.aws.amazon.com/amazonswf/latest/awsflowguide/dataconverters.html
Yes, it is going to break the replay. Replay is going to execute the workflow from the beginning and use DataConverter to deserialize activity results. If DataConverter changes then the activity result is going to change which might break workflow determinism.
BTW a change to an activity implementation that doesn't affect the activity input and output parameters is backwards compatible and doesn't require a version change.