RATPACK: CORE OF YOUR MICRO-SERVICES Ratpack reached version 1.0 in 2015. It’s a light-weight framework with a lot of potential. It has a good team and years for coding behind it, but still remains very straight-forward, easy to use, deploy, extend and at the same time it's very efficient and performing. Its core is non-blocking and implements reactive approaches for handling high-load with little resources. It has all you need for your micro-services.