Microservices have automated build and release processes. Take a look at the following figure. It shows a simple build and release process for a microservice:

When a microservice is built and released, a version of the microservice is stored in the repository. The deploy tool has the capability of picking the right version of microservice from the repository, matching it with the configuration needed for the specific environment (from the configuration repository), and deploying the microservice to a specific environment.

Some teams take it a step further and combine the microservice package with the underlying infrastructure needed to run the microservice. The deploy tool will replicate this image and match it with an environment-specific configuration to create an environment.