Sure, here is a PlantUML diagram that describes the Back for Frontend (BFF) pattern:

[See the image above]

In this diagram, we have three main components: the Backend, the Frontend, and the Back for Frontend (BFF) layer. The Backend provides the functionality to retrieve and create data, such as getting a customer by their ID, getting an order by its ID, and creating a new order. The Frontend is responsible for displaying information to the user, such as displaying an order by its ID.

The BFF layer sits between the Backend and Frontend and acts as an intermediary. It exposes a simplified API to the Frontend, which in turn communicates with the BFF rather than directly with the Backend. The BFF then performs any necessary operations on the Backend to fulfill the request and returns the result to the Frontend.

Note that the BFF in this diagram only exposes the `displayOrder` method, but in reality, it could expose other methods as well. This is just an example to illustrate the pattern.

Posted on Twitter by @me2resh