Astrid Atkinson listed seven factors which lead to successful teams in her keynote, which by proxy lead to business success:
There are a number of great Web features that are available to us today, yet few websites are utilising them. One example is the challenge of under-utilised bandwidth: currently, there is a delay while the browser downloads and parses the HTML document, discovers a
<link rel='stylesheet'> directive and requests the CSS asset(s) required to render the page.
This process takes time. This delay is unnecessary as the server already knows what assets are critical to render the page!
Preload is an HTML directive or HTTP header which hints to the browser that the linked asset should be pre-emptively loaded, as soon as possible. As an HTML directive it doesn’t offer much of a performance benefit in the described scenario. As an HTTP header however, it can offer a performance gain: the browser is made aware of a critical asset before the HTML is even downloaded.
HTTP/2 takes this paradigm one step further. HTTP/2 Server Push allows the server to actively push the asset to the browser. Cloudflare’s CDN currently implements this automatically when it sees the preload header.
Colin Bendell of Akamai spoke about the promise of Push. Although there is still some work to do on mainstream support (test your browser using Colin’s canipush.com), we can deploy Push now. Pushing CSS shows performance gains, while pushing anything else might actually make things worse.
<link rel='preload'> may still be the best option for WebFonts, for example.
Another technology mentioned a lot, again, was Progressive Web Apps. The magical combination of web app manifests, service worker and web push notifications which give us a near-native web app experience on Android devices. The fundamental technologies for PWAs have been around since mid-2015, and yet adoption is extremely low. Only 0.5% of mobile pages tested by HTTP Archive include a
Jason Grigsby gave an interesting keynote about PWAs. He explained that every step towards a PWA makes sense on its own. As such it’s shocking that web app manifests, the first step towards PWAs, have such a low penetration.
From speaking with my clients, it seems that there is a hesitance to ‘jump in to bed’ with PWAs. There are questions around the lack of support on iPhones as well as the feared erosion of native application market share. However, as Jason said, each step makes sense on its own. I recommend that my clients start work towards PWAs with a web app manifest and start to investigate the potential of service worker.
One of the key differentiating factors for the presentations I attended was whether the speaker empathised with their audience or not. By that I mean there were some speakers who had clearly thought about the Velocity audience and showed empathy for their pains and challenges at the very beginning of their talks. There were other speakers who appeared to be speaking for their own benefit, and had not thought about why the audience might want to hear what they have to say.
I’ll do my best to keep that in mind when speaking, I hope that others will do the same.