Composability is one of the service design principles. This leads to confusion about who is responsible for the composing services. In the SOA world, ESBs are responsible for composing a set of fine-grained services. In some organizations, ESBs play the role of a proxy, and service providers themselves compose and expose coarse-grained services. In the SOA world, there were two approaches for handling such situations.
The first approach is orchestration, which is depicted in the following diagram:
In the orchestration approach, multiple services are stitched together to get a complete function. A central brain ...