texas https://gitlab.com/dgmcguire/texas is a library that brings development back to the server. You can integration test without headless browsers, get SPA-like UX without writing a line of JS and basically just write SSR apps with only adding a few lines of code to make you apps realtime and SPA-like.
It works by leveraging persistent connections (websockets) first page load is entirely SSR and subsequent updates are SSR, but only by V-DOM diffing html fragments, sending only the minimum amount of patch data over the wire.
Your apps will be faster, your development process will be faster with less code and removing all kinds of complex tooling.
Here's a todoapp that does all rendering SSR https://warm-citadel-23442.herokuapp.com/ - you can see just how fast it is even on a free tier of heroku - open it up in multiple clients and you'll see that all operations are realtime broadcasted too and believe it or not there's only like 3 lines of code you write to make that happen (plus all the code necessary to get a normal SSR app running)