@Bsstahl @evan It's certainly doable, I'm thinking along the lines of Event Sourcing, but I'm curious: Are there any social-interaction-type things you have in mind? Like subscribing to tasks or todo-lists, commenting on items, etc.? Otherwise, essentially private-per-user, it's kind of hard to see the benefit over, say, a slightly fleshed out and secured REST-API a la http://www.todobackend.com/ :-P