Ehh, what you just described is often how service versioning works: launch a v2 service with the v1 still active, keep them running concurrently for a while, th

Ehh, what you just described is often how service versioning works: launch a v2 service with the v1 still active, keep them running concurrently for a while, then turn off the v1 when it's no longer used. You can distinguish the versions by using different endpoints, version fields, version headers, etc.. But that's just implementation details.