Remutable looks really impressive. I'm a little leery of the rest of it, though, as it means my backend is no longer a simple REST API. I'm also rather nonplussed that the full-stack Flux doesn't include optimistic display with loading icon, error state, and rollback handling out of the box. It doesn't even seem like an easy thing to do manually with this setup, though I haven't played with it enough to know.

Few minor questions: it looks like a base Remutable must be an Immutable.Map(). Can child items be any of the Immutable datatypes? Do we get updateIn() and similar?