“.. Twelve-factor processes are stateless and share-nothing. Any data that needs to persist must be stored in a stateful backing service. This factor remains relevant as written. …”

I am thinking that actor-based systems (like Erlang, or in the future Java-Loom based systems) – will not qualify to be the 12-factor apps, given that they would not rely on a specialized caching service to store the state. (or may be I am mis-interpreting this point)