This sounds slightly misleading to me: The primary driver is honestly encapsulation, so we can iterate faster as a company. Having a single, monolithic applica

This sounds slightly misleading to me: The primary driver is honestly encapsulation, so we can iterate faster as a company. Having a single, monolithic application codebase is not amenable to quick movement on a per-team basis. So when we decide to encapsulate something, then because of our performance concerns, its better to rewrite it in the JVM for most systems, than to write a new Ruby system. It sounds from that like their primary driver for using the JVM is actually performance, but that they only decide to rewrite components when encapsulation drives them to do so. I can't see how the JVM provides any encapsulation benefits over Ruby for new systems.