Extend Your Apps with External Add-ins: Figure 1: Don't Let Pipeline Overwhelm You.
It takes a lot of assemblies to create solid isolation, which can be frustrating because this isolation doesn't improve the first version of your app, when the host and add-in view can even be the same code. But, the adapters become essential in restructuring calls between disparate interfaces over time as different versions of the add-in, host, and contract need to work together. Regardless of which version you're working with, this design allows many hosts to work with the same add-in and many add-ins to work with the same host.
