Microservices enabled with RESTful APIs are the hot commodity these days. Microservices have emerged as the optimal unit of application development and deployment, not only for building and running enterprise-grade and production-ready applications, but also for modernizing currently-running applications. That is, legacy applications are being dismantled as a collection of microservices. Because of their unique features, microservices are becoming established as the most appropriate unit for migrating applications to cloud environments; that is, microservices contribute immensely to crafting and running cloud-enabled applications. Fresh applications are being directly developed in cloud environments, called cloud-native applications. This chapter discussed legacy modernization, why it's becoming essential, and how the MSA pattern assists in creating modern applications from outdated applications.

With the unprecedented adoption of the microservices architecture as the most beneficial architectural style for designing and developing next-generation business-critical and IoT applications, the RESTful paradigm has earned a new lease of life. That is, due to the simplicity and sustainability of RESTful APIs, microservices are increasingly stuffed with RESTful APIs. This book covered the practical and theoretical information aspects of how RESTful services and APIs contribute to futuristic and flexible web/cloud, mobile, and IoT applications.