Twitter is a one page application, yet it’s common to find twitts when searching on Google. I wonder what kind of technologies and methods does Twiiter use that make it so SEO friendly? IS it an isomorphic app that renders on the server?
Google doesn’t just look at the static html of your page. It loads the whole page including css/js in a browser and waits for some time and then takes a snapshot of the DOM and uses that.
That means you can use a 100% client rendered app and still have it be Google-friendly. Not sure about the support for this in other search engines, but google is all you need, then client rendered app should be fine.
There is a tool called Fetch As Google. You can see what Google crawler sees when it loads your page. That is what is going to be indexed.