In recent weeks Waldek Mastykarz, MS Developer Advocate, has spearheaded an information campaign about Microsoft Graph Connectors, which is wonderful as that service really deserves to be known by the SharePoint/M365 community.
A good handful of community members has provided a broad range of custom Graph Connectors and proven that creating a customer Graph Connector is within the capabilities of most organisations.
There are many good cases where a custom Graph Connector is the right choice for bringing 3rd party data into the M365 environment and thus breaking down the information silos which have caused employees to switch context repeatedly during a workday.
Yet, I have seen a few cases where I would recommend an Out Of The Box Microsoft provided Graph Connector over a custom Graph Connection.
The reason is not technical at all but more related to having a very clear segregation of responsibility between two or more parties.
Example:
Contoso Inc. has two suppliers and would like the information from one system to be available in another:
Supplier A is providing Building Inspection software as a SAAS solution and supplier B is providing an "Intranet In A Box" as a SAAS solution.
Since Supplier A is not providing a public API and isn't familier with M365 they will not be able to manage the Graph Connector required. Supplier B is very familiar with M365 but does not have access to the databases that supplier A is using in their SAAS solution.
In cases like this the obvious choice is to use an intermediate format that suits both parties. In one case Azure SQL was the right choice and in another case, Oracle was chosen as the common ground.
