Facade Pattern

It provides a single interface which hides the complex business logic resides in sub-systems and act as a single entry or exist point.

In microservice architecture, facade pattern can be seen at many places like in API Gateway, in microservice itself.
It’s also recommended to use when there is a need to perform business logic before or after making a call to other service. It hides the complexity which is required to make a request to external service or getting the modified response from it.
It can also be used as an ACL when there is a need to interact with legacy system.