We currently have this approach. One graphql backend-for-frontend server in front of an arbitrary number of BE servers. The UI always has a consistent interface

We currently have this approach. One graphql backend-for-frontend server in front of an arbitrary number of BE servers. The UI always has a consistent interface and the BE can focus on its business logic instead of how the FE should display it. The two layers can change fairly independently. We're still early in the project, but in theory I love this architecture and would use it again.