We have a mixture of Apollo v2 and Apollo v3 services running right now, and federation is working very well amongst them. We're about to start upgrading services to Apollo v4. There have been a lot of breaking changes with Apollo v4 so it occurs to me to ask: Has anyone successfully mixed Apollo v2/v3 and v4 in a federated GraphQL graph? Are there any gotchas we should be aware of?
We are in the process of updating some services to Apollo v4 now, but I don't see a lot of documentation on federation in the migration docs online.