Microservices is a software methodology for designing and developing software. It is an architectural style that structures an application to be composed of multiple smaller services. Each service exposes its operation via well-defined interfaces and is responsible for a single business requirement.
These services are independent of each other and this style of architecture consequently makes the application a collection of loosely-coupled services. The concept of microservices is aimed at developing an application that is loosely coupled, easily scalable, easily testable, and delivers the piece of software in a shorter interval of time.
Different microservices work together to form a larger application as a whole. They also communicate via unified, standard, well-defined interfaces.
The microservices architecture (MSA) is designed to separate the application into small, independent services, each one performing a specific functionality. These services are stateless and communicate with each other over the REST, regardless of the underlying platform it is developed in. The services are highly resilient, which means services are designed to be easily recoverable, which assume a high load or a failure.
Microservices has proven to be the capable model for developing a loosely-coupled system that is scalable, easily testable, and reduces the development cycle compared to single, large monolith applications. With Kotlin, it is much easier to develop such services and maintain such code bases.
To design microservices, we need to identify and design small services, each service performing one specific task. These smaller services form the building blocks of the microservices. For them to communicate, we need to define and choose the interface types so that the consuming service won't be tightly coupled to the other services. In addition, when interfaces are used, these services can be developed simultaneously; the services don't have to worry about the other service implementations, and they can have an independent life cycle from development up until deployment.