Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Site-Speed That Sticks

Avatar for Harry Roberts Harry Roberts
November 14, 2024
Technology
9
620

Site-Speed That Sticks

Avatar for Harry Roberts

Harry Roberts

November 14, 2024
Tweet

More Decks by Harry Roberts

See All by Harry Roberts
How to Think Like a Performance Engineer
Avatar for Harry Roberts csswizardry
24
1.7k
cache rules everything
Avatar for Harry Roberts csswizardry
5
3.4k
My Website Is Slow!
 Where Do I Start?
Avatar for Harry Roberts csswizardry
5
470
Optimising Largest Contentful Paint
Avatar for Harry Roberts csswizardry
37
3.3k
Get Your Head Straight
Avatar for Harry Roberts csswizardry
15
20k
From Milliseconds
 to Millions: A Look at the Numbers Powering Web Performance
Avatar for Harry Roberts csswizardry
1
2.5k
More Than You Ever Wanted to Know About Resource Hints
Avatar for Harry Roberts csswizardry
6
9.3k
It’s My (Third) Party, and I’ll Cry if I Want To
Avatar for Harry Roberts csswizardry
13
5.5k
FaCSSt: CSS & Performance
Avatar for Harry Roberts csswizardry
26
4.1k

Other Decks in Technology

See All in Technology
データ戦略部門 紹介資料
Avatar for Sansan, Inc. sansan33
PRO
1
3.1k
組織とセキュリティ文化と、自分の一歩
Avatar for mai miya maimyyym
3
1.4k
impressions-trying-lambda-web-adapter
Avatar for Junki Ishigaki junkishigaki
2
140
名刺メーカーDevグループ 紹介資料
Avatar for Sansan, Inc. sansan33
PRO
0
760
Digitization部 紹介資料
Avatar for Sansan, Inc. sansan33
PRO
1
4k
kintone開発組織のDevOpsへの移り変わりと実践
Avatar for Shin'ya Ueoka ueokande
1
280
TypeScript をより型安全に扱うプラクティス #TSKaigi #TSKaigi2025_kataritai
Avatar for 弁護士ドットコム bengo4com
0
2.1k
バクラクのモノレポにおける AI Coding のための環境整備と {Roo,Claude} Code活用事例 / AI Coding in Bakuraku's Monorepo: Environment Setup & Case Studies with {Roo, Claude} Code
Avatar for upamune / Yu SERIZAWA upamune
7
2.7k
Java 30周年記念! Javaの30年をふりかえる
Avatar for Yuichi.Sakuraba skrb
4
2.7k
libsyncrpcってなに？
Avatar for uhyo uhyo
0
240
dbt Cloudの新機能を紹介！データエンジニアリングの民主化：GUIで操作、SQLで管理する新時代のdbt Cloud
Avatar for Sagara sagara
0
110
Sansan Engineering Unit 紹介資料
Avatar for Sansan, Inc. sansan33
PRO
1
2k

Featured

See All Featured
ピンチをチャンスに：未来をつくるプロダクトロードマップ #pmconf2020
Avatar for Aki / @LoveIdahoBurger aki_iinuma
123
52k
Principles of Awesome APIs and How to Build Them.
Avatar for Keavy McMinn keavy
126
17k
KATA
Avatar for Megan Lloyd mclloyd
29
14k
Bash Introduction
Avatar for André Augusto Costa Santos 62gerente
614
210k
Automating Front-end Workflow
Avatar for Addy Osmani addyosmani
1370
200k
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
Avatar for soudai sone soudai
PRO
180
53k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
Avatar for Kevin Liebholz kevinliebholz
32
5.8k
Code Reviewing Like a Champion
Avatar for maltzj maltzj
524
40k
The Cost Of JavaScript in 2023
Avatar for Addy Osmani addyosmani
49
8.3k
BBQ
Avatar for Matthew Crist matthewcrist
89
9.7k
Unsuck your backbone
Avatar for Amy Palamountain ammeep
671
58k
Stop Working from a Prison Cell
Avatar for Chris Michel hatefulcrawdad
269
20k

Transcript

  1. site-speed that sticks

  2. None

  3. hi, i’m harry

  4. None

  5. five key topics

  6. 1. metrics 2. localhost 3. backstops 4. monitoring 5. playbook

  7. 1. metrics 2. localhost 3. backstops 4. monitoring 5. playbook

  8. 1. metrics 2. localhost 3. backstops 4. monitoring 5. playbook

  9. 1. metrics 2. localhost 3. backstops 4. monitoring 5. playbook

  10. 1. metrics 2. localhost 3. backstops 4. monitoring 5. playbook

  11. 1. metrics 2. localhost 3. backstops 4. monitoring 5. playbook

  12. metrics

  13. not all metrics are born equal

  14. different metrics for different people on different occasions with different

    levels of disclosure

  15. kpis, enablers, predictors

  16. kpis

  17. definition + target

  18. what are we working toward?

  19. of interest to the business

  20. core web vitals

  21. ‘which number on which dashboard of which service?’

  22. “We want a one-second improvement in Largest Contentful Paint.” —

    My Client
  23. None
  24. None
  25. None

  26. enablers

  27. metrics that directly influence kpis

  28. of interest to engineering teams

  29. ttfb, input delay

  30. predictors

  31. signals of good/bad performance

  32. highly quantitative

  33. of interest to engineers

  34. bundle size, long tasks, blocking css

  35. great for root-causing and reverse engineering

  36. localhost

  37. localhost is: seldom live-like, pretty dang fast, un-bundled

  38. know your tools inside out

  39. None
  40. None

  41. csswz.it/perfnow25

  42. one weird trick…

  43. None

  44. // plugins/delay.server.ts export default defineNuxtPlugin(async () => { await new

    Promise(resolve => setTimeout(resolve, 900)) })
  45. None
  46. None

  47. <head> <link rel=stylesheet href=https://slowfil.es/file?type=css&delay=800> </head>

  48. core web vitals are too big for localhost

  49. if you’re working locally, measure locally

  50. bare-metal metrics

  51. None
  52. None

  53. 1

  54. 1 2

  55. 1 2 3

  56. 1 2 3

  57. None
  58. None

  59. 1

  60. 1 2

  61. 1 2 3

  62. 1 2 3

  63. external: 1842ms inlined: 1250ms

  64. None

  65. these are very private metrics

  66. backstops

  67. …and budgets

  68. what is the worst possible performance we will accept?

  69. set it to the worst reading in the last release

    cycle
  70. None

  71. this is where synthetic testing comes into it

  72. synthetic testing; real user monitoring

  73. when to fail a release

  74. None

  75. predictors as tripwires

  76. None

  77. budgets versus targets

  78. budgets are backstops; targets are ambitions

  79. target == kpi

  80. None

  81. monitoring

  82. the m in rum stands for monitoring

  83. “Insanity is doing the same thing over and over again

    and expecting different results.” — Rita Mae Brown
  84. None

  85. 🎉

  86. ?

  87. None
  88. None
  89. None
  90. None

  91. it’s the exact same file

  92. None

  93. you’re monitoring variation in tests

  94. None

  95. only alert on your kpis

  96. None
  97. None

  98. 0.9952409649

  99. None
  100. None

  101. always follow the numbers

  102. playbook

  103. “Fighting regressions took priority over optimizations […]” — Michelle Vu,

    Pinterest
  104. None

  105. it’s all for nothing if you don’t have a plan

  106. response = f(severity, duration)

  107. severity

  108. acceptable: <10%

  109. moderate: 10–25%

  110. severe: 25–50%

  111. critical: >50%

  112. duration

  113. temporary: 24–48hr

  114. sustained: >48hr

  115. long-term: >1 release cycle

  116. unresolved: many release cycles

  117. a kpi regression of over 10% for one week requires

    remediation in the next sprint

  118. a kpi regression of over 100% for one hour requires

    rollback immediately

  119. a kpi regression of over 25% for one day requires

    remediation in the current sprint

  120. an enabler regression of over any% for any time needs

    the team’s attention over the next sprint

  121. a predictor regression of over any% for any time needs

    my attention over the next sprint

  122. you need a framework to fill in these blanks

  123. early triage

  124. who, what, when, where, and why?

  125. what?

  126. what has regressed?

  127. when?

  128. when did it start? is it still like that?

  129. where?

  130. is it a business-critical part of the site?

  131. who?

  132. who owns the problem?

  133. why?

  134. can you conduct early triage?

  135. None
  136. None
  137. None
  138. None
  139. None
  140. None

  141. key takeaways

  142. increase confidence

  143. use the right tool for the right job

  144. have a plan of attack

  145. agree; commit

  146. thank you

  147. harry.is/for-hire