The saved coroutine state is an implicitly-defined data structure and they don’t support any kind of migration when the code changes, so the durability will be quite limited.
It seems like generating some data structure definitions (similar to a protobuf) and checking them in along with the code would be useful? Then the compiler can tell you when they still match, or you made an incompatible change to the code.
This seems like a situation where defining the data structure in two different ways might be good?
The durable coroutine library is one part of a larger system we're releasing soon. See https://stealthrocket.tech/blog/fairy-tales-of-workflow-orch... for more information :)