What would you use nowadays to actually implement the real time GraphQL subscriptions and event system in practice?
We built https://github.com/hasura/graphql-engine , https://hasura.io that sets up the plumbing for this architecture with state being Postgres.
There’s a lot of other tooling emerging in this direction too. For example, set up a GraphQL server and subscriptions with Postgres and listen/notify and use SQS with lambda. Or dbezium + Kafka + custom service for event delivery.