What&#x27;s your impression of Elixir coming from Clojure, other than that?<p>I wanted to get into Clojure but I really wanted a language that almost entirely forced me to forego mutability (due to the large class of bugs I&#x27;ve seen in the past because of it) and Elixir seemed to provide that, Clojure did not, it was more live-and-let-mutability-live... and I didn&#x27;t like that.<p>Regarding your question, it&#x27;s my understanding that (again, due to everything being immutable), larger data sent between nodes in the same BEAM VM is <i>not</i> copied, it is reference-counted and garbage-collected and any changes are copy-on-write but only for that part of the data structure (due to implementation of Persistent Data Structures underneath).<p>One thing I&#x27;m VERY curious about with regards to Clojure is Datomic. Elixir (IMHO) could really use a fully queryable, immutable DB. After I drank the immutable kool-aid, it was jarring to have to think about mutation in global state again whenever I touch a database, to the point that I&#x27;m considering foregoing SQL as long as possible and just dealing with Mnesia or Basho&#x27;s Riak and writing implementation-agnostic wrappers around my datastores (the latter is probably a good idea anyway).<p>Mutexes need to die in a fire. ;)