As a software developer you are not very often in the situation where you develop a completely new system from scratch based on recent techonologies. More often just small features have to be integrated in already existing systems. A change of the basic software architecture and an introduction of new programming paradigms are very difficult in this context. It is all the more important to make the modernization of a legacy systems an ongoing part of the feature-driven development process. In this talk I will show step by step how to transform a big, monolithic legacy system towards a modern microservice based architecture. And I will demonstrate how two open libraries from Netflix can support this process. Hystrix will help us to improve the overall stability of the system and RxJava will help us to handle asynchronous processes in a more elegant way. Based on examples, I will show how the suggested modernization process could be realised.