Super grateful that Mandi Wise wrote that article and published the code on Github, would have been lost without it. That being said the federation-subscription-tools repo could use some love, there’s several PRs out by the community to fix some of the errors but no active maintainer. I was really hoping to see first-class support for subscriptions with the announcement of Apollo Federation 2.
As far as the approach, I think having a standalone subscription service is probably the right approach, but I think there’s room for improvement in the actually implementation. The current implementation example doesn’t allow for introspection over http/s. I’m working on a alternative approach right now based on Mandi Wise’s project but where the subscriptions lives along-side the federated gateway