&gt; Furthermore, let&#x27;s assume each module is its own actor and uses its own backend database.<p>I would have every module an actor type. There can be multiple types each type has its own schema. Within an actor type many actors. An actor for every product for instance. So all X widgets are in one actor.<p>&gt; With a monolithic database, there is no need to “lock” any resources, nor issue “confirmation tokens” - just use the DBMS&#x27;s built-in transaction system!<p>ActorDB has distributed ACID transactions so I would use that. You can create a transaction over multiple actors. The reason I would split it into many actors is that you&#x27;re always locking small parts of the system for the duration of the transaction not the entire DB.