The Decorator pattern is used to modify the behavior of a target component without changing its definition. This idea turns out to be pretty useful in the context of microservices because it can give you a better separation of concerns. It might even be necessary because the target service might be outside your control. This text looks at how a decorator can be implemented as a service, particularly one that sits between clients and a target service.

Example: an E-mail Service

Let’s introduce an example as a reference for our discussion.