Hmm. While it's nice to push rendering out to clients for saving your server CPU, that can lead to a suboptimal mobile experience, requiring more CPU and battery power on the mobile device to work on the javascript and render the page. There are other factors, for sure, but you want to be keeping client side javascript down to a minimum.<p>Taking a quick spin through yslow in the mobile browser suggests they've got a number of areas to improve on to make the time to screen significantly better on mobile devices (even on a fast connection here it took several seconds to even start showing me content, and several more before it had finally loaded everything)<p>Given the world wide reach of the BBC, expecting high speed and low latency networks seems like a bad idea. In the US, 3G & 4G typically see 90-100ms latency per request. Mobile Yslow is reporting that they've got 21 javascript scripts alone on the page. IIRC The android browser will limit itself to 4 threads retrieving content typically so that's (21/4 * 100ms) 525ms just lost in latency requesting the javascript, let alone actually downloading it and the overhead of the javascript renderer. It's also pulling in content from 21 different websites, so at the bare minimum that's 21 DNS calls being made (with the same latency penalty!) A bunch of those are being done just to load a single piece of content too, which is a little crazy.<p>Don't get me wrong, the site looks good.. it's just for a 'mobile-first' experience, they seem to be missing the all important time-to-screen and giving the mobile user a lot of work to do.<p>A useful tool from google for analysing the site for both mobile and desktop: <a href="https://developers.google.com/speed/pagespeed/insights/?url=http%3A%2F%2Fm.bbc.co.uk%2F" rel="nofollow">https://developers.google.com/speed/pagespeed/insights/?url=...</a><p>and a good talk from last year's Google I/O conference on optimising the mobile experience: <a href="https://www.youtube.com/watch?v=WrA85a4ZIaM" rel="nofollow">https://www.youtube.com/watch?v=WrA85a4ZIaM</a>