I'm guessing the main part of the content (for example the news story) is rendered server side, the client-side adds any personalisation if the user is logged in etc and adds panels for 'related'/most liked/read more news stories etc.
This means the content can be both crawled for SEO and cached (there's cache hit and fastly headers in their responses)
This means the content can be both crawled for SEO and cached (there's cache hit and fastly headers in their responses)