It is extremely rare that we see a software having only one microservice entirely. This perhaps might happen in case of certain POC (Proof of Concept) or prototype applications. Microservices always come in systems, meaning, we always have sets of microservices working together in a systemic manner to achieve the organizational goals. Microservices architecture does not mandate the use of particular technological artifacts, so it becomes a challenge to integrate if communication patterns and protocols are not implemented with certain agreed standards. Once we have common interface languages agreed upon, for example, JSON as data format, REST for HTTP-based service calls, and AMQP for messaging, we are ready to generate orchestrations.

Sometimes, we need to integrate with non-standard or unconventional communication patterns, sometimes we need to expose our APIs or microservices to a wide variety of clients, and sometimes, we need extra control and reports of how our microservices are consumed, and how they perform.

Let's see some of the patterns which are essential for integration of microservices for a number of use cases.