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Avatar for Peter Hedenskog Peter Hedenskog
September 04, 2014
Technology
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How to make your boss speed-curious and other webperf tricks - coldfront2014

My presentation from ColdFront2014:
http://coldfrontconf.com/

Avatar for Peter Hedenskog

Peter Hedenskog

September 04, 2014
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Transcript

  1. How to make your boss speed-curious and other #webperf tricks

    Peter Hedenskog
  2. None
  3. None

  4. The Performance Golden Rule!

  5. 80-90% of the end-user response time is spent on the

    frontend.

  6. front end dev

  7. front end dev

  8. front end dev

  9. front end dev

  10. front end dev

  11. front end dev

  12. With great power …

  13. comes great responsibility!

  14. 2

  15. How to be really fast

  16. The boss

  17. World fastest web page

  18. None

  19. Start render: 0,2 s Visually Complete: 0,2 s

  20. What can we learn?

  21. What CDN are you using?

  22. We know the Golden rule!

  23. The rendering path

  24. 1. Download HTML

  25. 2. If CSS files then download

  26. 3. If JS files then download

  27. 4. DOM + CSSOM = render tree

  28. 5. Paint

  29. Optimize the rendering path

  30. “I like thinking big.” Donald Trump

  31. “Think small” Peter Hedenskog

  32. What?

  33. super computers

  34. super fast internet

  35. remember

  36. mobile phones

  37. data

  38. the city

  39. magic number

  40. 14:ish kb

  41. High Performance Browser Networking - Ilya Grigorik Paul Irish

  42. focus

  43. above the fold

  44. “Think small” Peter Hedenskog

  45. Overall

  46. minimize

  47. combine

  48. avoid requests

  49. no requests

  50. HTML

  51. DOM node depth

  52. CSS

  53. inline

  54. <head> ... <style> body { background: #fff; } ... </style>

    </head> <body>

  55. https://github.com/filamentgroup/loadCSS

  56. None

  57. NEVER

  58. Avoid reflow and repaint

  59. None

  60. Javascript

  61. JAVASCRIPT CAN BE EVIL

  62. JAVASCRIPT IS EVIL* *inside your rendering path

  63. Synchronously loaded Javascript blocks the rendering path!

  64. Example of non working

  65. NEVER

  66. use async <script src=“/js/calculate.js” async></script> https://www.igvita.com/2014/05/20/script-injected-async-scripts-considered-harmful/

  67. measure above the fold

  68. User Timing API

  69. window.performance. mark(‘logoLoaded’);

  70. window.performance. measure(‘logoTiming’, ‘navigationStart’, ‘logoLoaded’);

  71. var items = window.performance .getEntriesByType(' measure');

  72. None

  73. There’s a polyfill for that!

  74. https://gist.github.com/pmeenan/5902672

  75. Demo

  76. front end dev

  77. The boss

  78. 2 kinds

  79. money

  80. http:// www.peterhedenskog.com/ blog/2014/09/more-speed- more-money/

  81. end user Be kind to your users! Mother Theresa

  82. < 0.1 second - instant < 1.0 second - flow

    =>10 seconds - lost ! Robert B. Miller - Response Time in Man-Computer Conversational Transactions (1968) The brain

  83. Visualize

  84. Your boss understands red, yellow and green

  85. 1200 ms

  86. red 1200 ms

  87. yellow 1200 ms

  88. green 1200 ms

  89. None

  90. x

  91. we are 12% slower than …

  92. None

  93. summary

  94. front end dev

  95. None

  96. small

  97. None

  98. •Peter in Denmark - Lars Von Trier •Donald Trump -

    Gage Skidmore •Super computer - Zdjęcia Arkadiusz Sikorski •Monkey with iphone - Marsel Van Oosten •The house - Bert Kaufmann •Stop light peppers - Dennis S Hurd •What is this? - Jeff Carson •Corcovado jesus - Doug88888 •Developers - Austin Wordpress Camp •The evil king - HBO •Pippi Longstocking - Ingrid Vang Nyman •Montgomery Burns - Matt Groening •The dog - Emiliano •Paint over - franziska •Super heroes - Marvel •Vee - Netflix Image credits

  99. Thank you! Peter Hedenskog [email protected] @soulislove