This looks similar to how Meteor's ReactiveVar package, and lower-level Tracker library, works: <a href="https://docs.meteor.com/api/reactive-var.html" rel="nofollow">https://docs.meteor.com/api/reactive-var.html</a><p>It's certainly helped make building real-time user interfaces that update when the data changes significantly easier in my opinion, because you're able to express your intent in code more closely to what you mean rather than having to write all the connecting reactive boilerplate yourself.