As mentioned several times in this book, MSA is being positioned as the next-generation application architectural pattern. Microservices are constructed, compiled, and deployed as a separate project. Containers are the most optimal unit of microservices development and deployment. Every microservice is blessed with its own data store. They aren't compiled into software solutions. Instead, they're implemented as standalone services to be integrated and orchestrated via standards-based and communication protocols.

Every service is being given an interface using the simple-to-use RESTful APIs. Microservices are carefully versioned not to adversely affect any other user microservices and applications. For example, for a business-to-consumer (B2C) e-commerce application, a microservice may be developed to provide a products catalog. Another microservice takes care of procurement, another is for payment, and so on. Thus, microservices are independently developed by distributed teams and then deployed.

Complicated and sophisticated applications are being constructed through the leverage of microservices. On the other side, massive applications are being dismantled into a collection of microservices.

Microservices are typically small and independent processes that communicate with one other using well-defined and language-agnostic APIs. They are usable, reusable, interoperable, dynamically-composable, and self-defined. Microservices expose their unique and business-centric capabilities through well-intended interfaces to the outside world. Thus software integration gets simplified and sped up in a formalized manner. There are cross-cutting concerns and horizontal (business-agnostic) functions that usually get replicated across the source code for any enterprise-grade software system. They can be centralized using microservices. Some functions have to be frequently updated and upgraded using advanced technologies. Thus, not only application development, but also the maintenance aspect are both worrisome factors for worldwide enterprises. These specialized functionalities can be built as microservices and then exposed so they can be easily found and bound in software applications.