I think I'm too biased to answer this properly. :) All of the realtime-as-a-service options have good resiliency. Pair one of them with RESTful AJAX for the cha

I think I'm too biased to answer this properly. :) All of the realtime-as-a-service options have good resiliency. Pair one of them with RESTful AJAX for the chat db/logic and you'll do well.