Basically, it is chrome manager, that loads needed templates into tabs or iframes And then provides concurent way to apply js and get render as screenshot back.
In our case - we doing commits from backends directly into Vuex store and after having screenshot on Vue.$nextTick user receives his data.
Working example can be found at telegram @Benice_tools_bot (link)
We are preparing our sources for publishing. Please click star if you interested.