Great question. Our DC/OS infrastructure currently runs solely out of AWS. Our reduction of instances is driven purely by densification of our infrastructure. Our event streaming infrastructure is fairly complex with multiple technologies involved (Kafka, Zookeeper, RabbitMQ, Redis, etc...), this can quickly bloat your instances. With some careful planning around the resources we allocated per container, we were able to get far better density w/ multiple containers per instance. I'd say we have further opportunity for optimization. Optimizations that will both improve our density (better placement, improved app code and design, etc.), and optimizations that may slightly reduce our density (place to avoid resource contention, etc.). Placement and resource allocation is definitely an art form :-)