SSR gets you most of the way there... your code just has to respect the URL as the 'global state' and turning any user input into link-based data (ie, click this, provide a URL, process the URL).
I wish all javascript websites would do this too. Unlinkable stuff grinds my gears =)
Are there still (browser) limits on how long such a URL can be? Would it e.g. be possible to store a text of 50.000 words in the URL alone?
My goal with this post and demo was to outline a general strategy that could be employed in both small and large applications. For some cases, you could implement the server-side dispatching of actions as listening on GET-requests, but you would potentially be polluting the browser history more than necessary, and be capped to ~2k characters (varies in browsers) for actions (which for many cases should suffice).
I imagine that keeping all _state_ in the URL, while it can work for some small applications, might not scale sufficiently to be a general approach to the problem, nor have the kind of persistence usually found in eg. applications with login, where a user might expect to be able to authenticate and continue where they left off.