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Comment by CharlesW | Hacker News Reader

Are you arguing for or against SSR here? (Both would include base HTML, no?)

A single page application (SPA) without server side rendering (SSR) doesn't serve "useful data to the user on the first payload". It serves an empty HTML shell with a script tag (or multiple tags) linking to the Javascript app bundle (or multiple bundles). If the app bundling doesn't break up the app into smaller bundles that are asynchronously loaded, the initial JS payload will probably be 10+ MB. At which point the browser needs to download the 10 MB of JS, execute it, and have the JS fill in the HTML with "useful data".

So no, an SPA without SSR doesn't include useful data in the first payload.

10mb of JS — Examples?

I was going to say Slack but it "only" transferred 5MB.

10 MB could be an exaggeration on average, but not by a huge amount. Not even trying to find something crazy big, this is the first site I checked because I went to it earlier today and noticed it took a long time to load:

https://help.salesforce.com/articleView?id=000232181&languag...

It is simple help article, but instead of serving the actual help article it spends about 2 seconds serving 4 MB of JS and rendering the article.

After that I typed 'app.' into my URL bar and went to the first site that came up, that was 3.9 MB of JS on the login page.

Numbers are for uncompressed JS, including the larger of the inline scripts.

https://petermolnar.net/the-three-facebooks/

For one example of JS-dumbfuckery, the Patreon embed button is served as a React app, with all of React bundled in dev-mode, weighing in at just over 2mb.

All of that for a red rectangle with the word "Patreon" in the middle.

There are patterns (prerendering, streaming (https://jakearchibald.com/2016/streams-ftw/#streaming-result...), etc.) other than simply breaking up the JS app bundle into smaller pieces that can alleviate the traditional "SPA concerns" — hopefully you can just reduce its size overall.

For other thoughts and ideas regarding SSR pros and cons, checkout this presentation given at Polymer Summit (http://www.youtube.com/watch?v=wYGoJ8R3nnM&t=5m35s).

If you are serving 10MB of JS, then you have a lot more optimizing to do way before you need to think about SSR.

A Phoenix + React application I'm working on uses react-stdio to render React components server side and speed up page load time when users get to the site for the first time or reload the page in the browser for whatever reason.

We ended up with a few hundred MB of RAM for Elixir and a few GB for the Node.js servers. Basically our machines are JavaScript application servers with a little bit of Elixir running in a corner. It feels so odd.

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