Blanket statements like &quot;Cassandra doesn&#x27;t work&quot; and &quot;Hadoop is a complete waste of hosts for most companies&quot; are unproductive and contribute nothing, unless you can back them with data and real world examples.<p>So, what data do you base these assertions on ? Also, not to burst your bubble but a lot of businesses (if not the majority) run Spark on YARN. And Spark is built on the JVM.