Doesn't Hasura or Postgraphile do this better? They give a GraphQL API over Postgres with support for subscriptions, along with authentication, authorization etc.
You could shoehorn hasura for this usecase but those tools are primarily intended for frontend clients to subscribe to a schema you expose.
Change data capture allows you to stream database changes to a message bus or stream which has much better support for backend service requirements. Example: if a downstream service goes down, how would it retrieve the missed events from Hasura? Using Kafka or a buffered message bus, you'd be able to replay events to the service.
Nevermind having to support websockets in all your services :/
