How would you do it? The speed of light being what it is, and tail latencies being large unless you over provision wildly, you keep facing hundreds of milliseconds of reconciliation time, if you want guaranteed synchronous result.

I said it in another thread. Yes, of course we cannot match the local store interactivity. What I mean is coast to coast RTT is 65-80ms. And the server can be optimized to return back basic operations (adding a comment, a new ticket, reading one back etc) can be done within tens of milliseconds, keeping the entire thing under 100ms coast-to-coast. If one can colocate servers with users, it becomes even less. I'd rather to server side "reconciliation" than do both (because serverside thing doesnt go away even with localstore, it is just deferred).