[izym]

> Breaking the behavior of my back button is one of the worst user experiences I get these days. Usually it makes me so angry that I just leave the site right away.

Obviously that is not the wanted user experience. Disregarding SPAs as a solution because of an unintended behaviour is kind of throwing the baby out with the bath water.

> Browsers can do that on their own since forever, given a carefully crafted HTML page.

How are you rendering parts of something from a server before receiving anything from the server using only HTML? I'm talking about the following flow:

1. User clicks link

2. Instantly the layout etc. is rendering using JS, with fancy loading elements (maybe ala how FB does their news feed) for the missing items

3. The data is loaded and put into the layout

Whereas for the non-SPA flow the user would have to wait for data to be received before anything is rendered. Of course pre-fetching alleviates this a bit, but it still requires the whole page to re-render.