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Breaking news at 1000ms - Front-Trends 2014

Breaking news at 1000ms - Front-Trends 2014

An introduction into how the Guardian are making their next generation website load as fast as possible, and ultimately breaking the news to the user within 1000ms.

During the talk you will discover why performance matters, what are the common performance bottlenecks in the browser from networking to painting and learn how to best optimise and monitor each stage of the critical path to create fast, jank free websites.

Patrick Hamann

May 08, 2014
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  1. 0 2.25 4.5 6.75 9 2000 2006 2009 2012 User

    load time expectations (Secs) User load time expectations are decreasing Source: Web Performance Today - March 2013
  2. 0 5000 10000 15000 20000 Jan Feb Mar Apr 10%

    Percentile Median 90% Percentile Average SpeedIndex top 10,000 websites Source: HTTPArchive - May 2014
  3. Maslow's hierarchy of user needs • We surveyed 3000 users

    • About 17 key product drivers • They rated speed 2nd most important • Only after easy to find content
  4. Time & user perception Delay User perception 0–100 ms Instant

    100–300 ms Small perceptible delay 300–1000 ms Machine is working 1,000+ ms Likely mental context switch 10,000+ ms Task is abandoned Source: Ilya Grigorik – High-Performance Browser Networking
  5. – Tim Kaldec - 2013 A performance budget is just

    what it sounds like: you set a “budget” on your page and do not allow the page to exceed that. This may be a specific load time, but it is usually an easier conversation to have when you break the budget down into the number of requests or size of the page.
  6. 1. Core content should be delivered first 2. Core content

    should render within 1000ms 3. Every feature must fail gracefully 4. Every request should be measured
  7. 1. Core content should be delivered first 2. Core content

    should render within 1000ms 3. Every feature must fail gracefully 4. Every request should be measured
  8. 1. Core content should be delivered first 2. Core content

    should render within 1000ms 3. Every feature must fail gracefully 4. Every request should be measured
  9. Network JavaScript Render tree Layout Paint HTML DOM CSS CSSOM

    Network JavaScript Render tree Layout Paint HTML DOM CSS CSSOM Network JavaScript Render tree Layout Paint HTML DOM CSS CSSOM DOM
  10. Load time First byte Start render Visually complete 3.366s 0.204s

    1.113s 3.700s Before Load time First byte Start render Visually complete 3.017s 0.262s 0.759s 2.00s After
  11. 1. Core content should be delivered first 2. Core content

    should render within 1000ms 3. Every feature must fail gracefully 4. Every request should be measured
  12. – W3C Font Spec ! ! ! User agents may

    render text as it would be rendered if downloadable font resources are not available or they may render text transparently with fallback fonts to avoid a flash of text using a fallback font. ! In cases where the font download fails user agents must display text, simply leaving transparent text is considered non-conformant behaviour.
  13. Font loading 101 IE Firefox WebKit Blink Blocking ✗ ✔

    ✔ ✔ Timeout – 3s – – Source: Ian Feather – Web fonts and the Critical Path
  14. Is modern browser? Support WOFF? Font in localStorage? Show font

    Show fallback Download JSON localStorage space? Cache in localStorage
  15. 1. Core content should be delivered first 2. Core content

    should render within 1000ms 3. Every feature must fail gracefully 4. Every request should be measured
  16. 1. Core content should be delivered first 2. Core content

    should render within 1000ms 3. Every feature must fail gracefully 4. Every request should be measured