[buro9]

I mostly agree with this.

I consider services to fall into two groups:

1. Core/Technical services that are the master record for data and are responsible for data integrity, notifying others of changes, audit, etc... but ultimately store the data and the schemas of a piece of data, handle caching.

2. Composition/Orchestration/Business services that sit in front of the core services, and these contain business logic and when they operate on lists they really operate on IDs and do that ESI merge thing composing their collection from multiple calls from the core service.

The more I work on services the more I find this separation and layering of services extremely useful. It helps massively simplify the services that interact with data stores, and allows for quick development of new composition services to handle new needs of the business.