Hard to answer that with concrete numbers but Om Next handles optimistic and non-optimistic updates quite elegantly. Roughly speaking: each query expression is

Hard to answer that with concrete numbers but Om Next handles optimistic and non-optimistic updates quite elegantly. Roughly speaking: each query expression is parsed twice, once locally and once in remote mode, and as long as your backend can handle Om Next query expressions, it Just Works: Reading: https://github.com/swannodette/om-next-demo/blob/master/todomvc/src/cljs/todomvc/parser.cljs#L25 https://github.com/swannodette/om-next-demo/blob/master/todo... Mutating: https://github.com/swannodette/om-next-demo/blob/master/todomvc/src/cljs/todomvc/parser.cljs#L60 https://github.com/swannodette/om-next-demo/blob/master/todo...