Depends on the project. Lots of cases when there's no need for schema versioning. For example, when two processes need to talk to each other and they both run f

Depends on the project. Lots of cases when there's no need for schema versioning. For example, when two processes need to talk to each other and they both run from the same binary or share the exact same datamodel. Even if they aren't run from the same binary, it's often much simpler to just require both sides to use the same protocol revision.