🇮🇨 JSDay Canarias 2023

ℹ️ Hydration, Islands, Streaming, Resumability… Oh My!

Our ecosystem can be overwhelming! First, we had the rise of SSR and SSG—and each had its own gigantic pile of frameworks and tools. Then partial hydration enabled us to hydrate only some of our components on the client, which we've seen in React Server Components.

But what about islands? Do they relate at all to Streaming SSR? Moreover, what is resumability, and why do I keep hearing about it? […] Oh, did anyone say rendering on the Edge?

Well… There are many approaches out there, and all of them argue that their philosophy is best. In this session, we’ll go over these architecture/rendering patterns, to help shed some light on how some are implemented and the concepts behind them.

Transcript

1. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! • THE 27TH OF MAY, 2023. Hello, JSDay Canarias 👋 🇮🇨
2. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! 🤯 MATHEUS ALBUQUERQUE • @ythecombinator
3. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! ↑ ALL THE LINKS! 🤓 🧑🏫 @techlabs 🐦 @ythecombinator 👨💻 @medallia ⚡ Perf GDE
4. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! ↑ ALL THE LINKS! 🤓 🍺 LET’S DISCUSS MORE AFTER!
5. #disclaimer 😌 This is for those who like to see what’s behind the curtain. You don’t have to know all of that to be productive with front-end development.
6. This talk presents… ↝ The Past & The Future ↝ Islands Architecture ↝ Resumability ↝ Streaming SSR + Selective Hydration ↝ React Server Components ↝ Closing Thoughts
7. #question 🤔 How and where do I want to render content?
8. HOW AND WHERE DO I WANT TO RENDER CONTENT? web server build server the Edge the client
9. web server build server the Edge the client all at once partially progressively HOW AND WHERE DO I WANT TO RENDER CONTENT?
10. AND MORE! all at once partially progressively Where do you navigate? When do you load? What is executed on load? When is data fetched? What do you bundle/serialize? web server build server the Edge the client
11. #question 🤔 How did we get here?
13. The Past HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
16. ↝ LANGUAGES LIKE PERL AND PHP ALLOWED DEVELOPERS TO RENDER BACKEND DATA SOURCES INTO HTML ↝ DEVELOPERS WERE NOW ABLE TO BUILD DYNAMIC SITES AND SERVE REAL-TIME DATA, OR DATA FROM A DATABASE TO AN END USER CGI SCRIPTING LANGUAGES
17. ↝ THESE WORKED ON THE SERVER BECAUSE SERVERS WERE THE POWERFUL PART OF THE NETWORK ↝ THE BROWSER'S JOB WAS LIMITED: INTERPRETING THE DOCUMENT AND SHOWING THE PAGE ↝ THIS SOLUTION WAS ALL ABOUT SHOWING INFORMATION, NOT INTERACTING WITH IT CGI SCRIPTING LANGUAGES
18. #eureka 💡 JavaScript and browsers got powerful = we could do a ton of fun things directly on the client.
19. ↝ ONCE EVERYTHING IS IN PLACE, YOU DON’T HAVE TO GO BACK TO THE SERVER FOR MORE REQUESTS ↝ YOU CAN CACHE THE CORE HTML AND JS BUNDLES ON A CDN ↝ AS THE WEB GOT MORE INTERACTIVE, CSR AND SPAS BECAME DEFAULT CLIENT-SIDE RENDERING (CSR)
20. #gotcha 🥸 We now had to be mindful of how our apps would render on a phone on a bus in the city center.
21. #eureka 💡 We now had to be mindful of how our apps would render on a phone on a bus in the city center. Back to the server! 🏃
23. ↝ HTML IS READY TO BE DISPLAYED WHEN THE PAGE IS LOADED = HIGHER PERFORMANCE ↝ HTML IS NOT DEPENDENT ON THE END BROWSER = HIGHER COMPATIBILITY ↝ FOR INTERACTIVE WEBSITES, WE STILL NEED TO SEND JS = HYDRATION SERVER-SIDE RENDERING (SSR)
24. 🚨 INTERMISSION: Hydration HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
25. #definition 🧐 Hydration is the process of attaching behavior to declarative content to make it interactive. — WHY PROGRESSIVE HYDRATION IS HARDER THAN YOU THINK, BY MIŠKO HEVERY
26. ↝ ASSOCIATE DOM ELEMENTS WITH THEIR CORRESPONDING EVENT HANDLERS ↝ ONCE A USER EVENT TRIGGERS A HANDLER, WE NEED TO UPDATE THE APP STATE ↝ ONCE THE APP STATE UPDATES, THE FRAMEWORK NEEDS TO RECREATE THE COMPONENT HIERARCHY HYDRATION: CHALLENGES 🍺
27. ↝ DO WE SEND ALL JS ON EVERY REQUEST? OR DO WE BASE IT ON THE ROUTE? ↝ IS HYDRATION DONE TOP-DOWN? AND HOW EXPENSIVE IS THAT? ↝ HOW DOES THE DEVELOPER ORGANIZE THE CODE BASE? HYDRATION: QUESTIONS 🍺
28. Islands Architecture HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! 1993 1998 2008 2017 2020 2021 2022
29. ↝ SELECTIVELY, PROGRESSIVELY ENHANCING BITS OF SERVER-RENDERED HTML WITH CLIENT-SIDE JS ↝ SMALL, FOCUSED, CHUNKS OF INTERACTIVITY WITHIN SERVER-RENDERED WEB PAGES ↝ SINGLE APPLICATION IN CONTROL OF FULL-PAGE RENDERING → MULTIPLE ENTRY POINTS ISLANDS ARCHITECTURE
30. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
31. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
32. ↝ THE SCRIPT FOR THE ISLANDS CAN BE DELIVERED AND HYDRATED INDEPENDENTLY, ALLOWING THE REST OF THE PAGE TO BE JUST STATIC HTML ↝ THE OUTPUT OF ISLANDS IS PROGRESSIVELY ENHANCED HTML ↝ MORE SPECIFICITY AROUND HOW THE ENHANCEMENT OCCURS ISLANDS ARCHITECTURE
33. #definition 🧐 Islands are a component-based architecture that suggests a compartmentalized view of the page with static and dynamic islands. — ISLANDS ARCHITECTURE, BY PATTERNS.DEV
34. ISLANDS ARCHITECTURE PAGE LAYOUT POST TITLE POST CONTENT COMMENTS SOCIAL CTA
35. ISLANDS ARCHITECTURE PAGE LAYOUT (SSR’D) POST TITLE (SSR'D) POST CONTENT (SSR’D) COMMENTS PLACEHOLDER (SSR) SOCIAL CTA PLACEHOLDER (SSR) COMMENTS “APP” (SSR’D + HYDRATION SCRIPT) SOCIAL CTA “APP” (SSR’D + HYDRATION SCRIPT)
36. ISLANDS ARCHITECTURE PAGE LAYOUT (SSR’D) POST TITLE (SSR'D) POST CONTENT (SSR’D) COMMENTS PLACEHOLDER (SSR’D) SOCIAL CTA PLACEHOLDER (SSR’D) COMMENTS “APP” (SSR’D + HYDRATION SCRIPT) SOCIAL CTA “APP” (SSR’D + HYDRATION SCRIPT)
37. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
38. ↝ STREAMING RENDERING + AUTOMATIC PARTIAL HYDRATION + COMPILER ↝ AUTOMATIC PARTIAL HYDRATION ALLOWS INTERACTIVE COMPONENTS TO HYDRATE THEMSELVES ↝ HYDRATION CODE IS ONLY SHIPPED FOR INTERACTIVE COMPONENTS ISLANDS ARCHITECTURE (WITH MARKO) 🍺
39. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
40. ↝ BY DEFAULT, SHIPS ZERO JAVASCRIPT ↝ EVERY ISLAND IS LOADED IN PARALLEL ↝ YOU CAN SPECIFY THE LOADING STRATEGY FOR EACH ISLAND INDIVIDUALLY ↝ MULTI-FRAMEWORK: BUILD ISLANDS WITH REACT, PREACT, SVELTE, VUE, AND OTHERS ISLANDS ARCHITECTURE (WITH ASTRO)
41. - - - import MyReactComponent from ' . . /components/MyReactComponent.jsx'; - - - <MyReactComponent /> ISLANDS ARCHITECTURE (WITH ASTRO)
42. - - - import MyReactComponent from ' . . /components/MyReactComponent.jsx'; - - - <MyComponent client:load /> <MyComponent client:idle /> <MyComponent client:visible /> <MyComponent client:media={string} /> <MyComponent client:only={string} /> ISLANDS ARCHITECTURE (WITH ASTRO)
43. ↝ STANDALONE/METAFRAMEWORK: Astro, Iles, Qwik, Marko, Nano JSX, Capri ↝ 11TY: is-land, Slinkity ↝ PREACT: Fresh, preact-island, microsite ↝ SOLIDJS: Solid Start, isolid ↝ SVELTE: Elder.js ISLANDS ARCHITECTURE
44. #case💡 An e-commerce. Product pages have static descriptions and links. Interactive components (e.g., image carousels, search bar) are available in different regions.
45. #case💡 An internet banking app. The account details page contains a list of static transactions with filters providing some interactivity.
46. 🟢 REDUCES THE AMOUNT OF JAVASCRIPT CODE SHIPPED TO THE CLIENT 🟢 FASTER PAGE LOADS AND TIME TO INTERACTIVE (TTI) 🟢 KEY CONTENT IS AVAILABLE ALMOST IMMEDIATELY TO THE USER 🟢 STATIC CONTENT IS RENDERED ON THE SERVER = PAGES ARE SEO-FRIENDLY GREAT 🟡 HIGHLY INTERACTIVE PAGES WOULD PROBABLY REQUIRE THOUSANDS OF ISLANDS NOT GREAT ISLANDS ARCHITECTURE
47. 🟢 REDUCES THE AMOUNT OF JAVASCRIPT CODE SHIPPED TO THE CLIENT 🟢 FASTER PAGE LOADS AND TIME TO INTERACTIVE (TTI) 🟢 KEY CONTENT IS AVAILABLE ALMOST IMMEDIATELY TO THE USER 🟢 STATIC CONTENT IS RENDERED ON THE SERVER = PAGES ARE SEO-FRIENDLY GREAT 🟡 HIGHLY INTERACTIVE PAGES WOULD PROBABLY REQUIRE THOUSANDS OF ISLANDS NOT GREAT ISLANDS ARCHITECTURE
48. Resumability HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! 1993 1998 2008 2017 2020 2021 2022
49. #hotTake 🌶 A considerable part of the modern isomorphic landscape is built on the back of libraries that weren't initially created for server rendering.
50. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
51. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
52. HYDRATION: THE BAD PARTS™ INITIAL REQUEST HTML ARRIVES VIEW PAINTED JAVASCRIPT ARRIVES JAVASCRIPT IS PARSED — RESUMABILITY, WTF?, BY RYAN CARNIATO 0 100
53. HYDRATION: THE BAD PARTS™ GET HTML DOWNLOAD JS PARSE + EXECUTE JS RECOVER STATE + BIND LISTENERS
54. HYDRATION: THE BAD PARTS™ GET HTML DOWNLOAD JS PARSE + EXECUTE JS RECOVER STATE + BIND LISTENERS 🟢 FAST (USUALLY)
55. HYDRATION: THE BAD PARTS™ GET HTML DOWNLOAD JS PARSE + EXECUTE JS RECOVER STATE + BIND LISTENERS 🔴 SLOW (ON BAD NETWORK CONDITIONS)
56. HYDRATION: THE BAD PARTS™ GET HTML DOWNLOAD JS PARSE + EXECUTE JS RECOVER STATE + BIND LISTENERS 🔴 SLOW (DEPENDING ON THE DEVICE AND AMOUNT OF JAVASCRIPT)
57. HYDRATION: THE BAD PARTS™ GET HTML DOWNLOAD JS PARSE + EXECUTE JS RECOVER STATE + BIND LISTENERS 🔴 SLOW (DEPENDING ON THE AMOUNT OF DOM NODES TO BE TRAVERSED AND REFERENCES TO BE RE-BOUND TO LISTENERS)
58. #question 🤔 What if frameworks were built on SSR in the first place?
59. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
60. OPA LANGUAGE 🍺
61. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
62. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
63. HYDRATION → RESUMABILITY GET HTML DOWNLOAD JS PARSE + EXECUTE JS RECOVER STATE + BIND LISTENERS GET HTML 🔴 READY 🟢 READY
64. #definition 📖 Resumability is about pausing execution in the server and resuming execution in the client without having to replay and download all of the application logic. — RESUMABLE VS. HYDRATION, QWIK
65. ↝ SOME WORK → PAUSE → RESUME ↝ USE WHAT HAPPENED DURING THE EXECUTION ON THE SERVER AND AVOID EXTRA WORK WHEN THE APPLICATION STARTS IN THE BROWSER ↝ ATTACHES GLOBAL EVENT HANDLERS AT STARTUP AND THEN ONLY RUNS THE NECESSARY CODE ON INTERACTION RESUMABILITY
66. ↝ EVENT HANDLER CREATION HAPPENS BEFORE THE EVENT IS TRIGGERED (EAGER) ↝ ALL POSSIBLE EVENT HANDLERS ARE CREATED AND REGISTERED (SPECULATIVE) ↝ CLIENT REDOES WORK ↝ REQUIRES THE FRAMEWORK TO DOWNLOAD AND EXECUTE THE COMPONENTS TO FIGURE OUT HIERARCHY HYDRATION ↝ EVENT HANDLER CREATION HAPPENS AFTER THE EVENT IS TRIGGERED (LAZY) ↝ ONLY TRIGGERED EVENTS ARE CREATED AND REGISTERED (AS-NEEDED) ↝ CLIENT DOESN'T REDO WORK (VIA DESERIALIZATION) ↝ REQUIRES ALL THE INFORMATION TO BE SERIALIZED IN THE HTML RESUMABILITY HYDRATION VS. RESUMABILITY
67. ↝ EVENT HANDLER CREATION HAPPENS BEFORE THE EVENT IS TRIGGERED (EAGER) ↝ ALL POSSIBLE EVENT HANDLERS ARE CREATED AND REGISTERED (SPECULATIVE) ↝ CLIENT REDOES WORK ↝ REQUIRES THE FRAMEWORK TO DOWNLOAD AND EXECUTE THE COMPONENTS TO FIGURE OUT HIERARCHY HYDRATION ↝ EVENT HANDLER CREATION HAPPENS AFTER THE EVENT IS TRIGGERED (LAZY) ↝ ONLY TRIGGERED EVENTS ARE CREATED AND REGISTERED (AS-NEEDED) ↝ CLIENT DOESN'T REDO WORK (VIA DESERIALIZATION) ↝ REQUIRES ALL THE INFORMATION TO BE SERIALIZED IN THE HTML RESUMABILITY HYDRATION VS. RESUMABILITY
68. ↝ EVENT HANDLER CREATION HAPPENS BEFORE THE EVENT IS TRIGGERED (EAGER) ↝ ALL POSSIBLE EVENT HANDLERS ARE CREATED AND REGISTERED (SPECULATIVE) ↝ CLIENT REDOES WORK ↝ REQUIRES THE FRAMEWORK TO DOWNLOAD AND EXECUTE THE COMPONENTS TO FIGURE OUT HIERARCHY HYDRATION ↝ EVENT HANDLER CREATION HAPPENS AFTER THE EVENT IS TRIGGERED (LAZY) ↝ ONLY TRIGGERED EVENTS ARE CREATED AND REGISTERED (AS-NEEDED) ↝ CLIENT DOESN'T REDO WORK (VIA DESERIALIZATION) ↝ REQUIRES ALL THE INFORMATION TO BE SERIALIZED IN THE HTML RESUMABILITY HYDRATION VS. RESUMABILITY
69. RESUMABILITY: SERIALIZATION { "handlers": [ … ], "state": { … }, "hierarchy": { … }, } DISPLAY HTML RESUME STATE (JSON PARSE) 🟢 INTERACTIVE
70. RESUMABILITY: SERIALIZATION { "handlers": [ … ], "state": { … }, "hierarchy": { … }, } DISPLAY HTML RESUME STATE (JSON PARSE) 🟢 INTERACTIVE
71. RESUMABILITY: SERIALIZATION { "handlers": [ … ], "state": { … }, "hierarchy": { … }, } DISPLAY HTML RESUME STATE (JSON PARSE) 🟢 INTERACTIVE
72. ↝ EVENT HANDLER CREATION HAPPENS BEFORE THE EVENT IS TRIGGERED (EAGER) ↝ ALL POSSIBLE EVENT HANDLERS ARE CREATED AND REGISTERED (SPECULATIVE) ↝ CLIENT REDOES WORK ↝ REQUIRES THE FRAMEWORK TO DOWNLOAD AND EXECUTE THE COMPONENTS TO FIGURE OUT HIERARCHY HYDRATION ↝ EVENT HANDLER CREATION HAPPENS AFTER THE EVENT IS TRIGGERED (LAZY) ↝ ONLY TRIGGERED EVENTS ARE CREATED AND REGISTERED (AS-NEEDED) ↝ CLIENT DOESN'T REDO WORK (VIA DESERIALIZATION) ↝ REQUIRES ALL THE INFORMATION TO BE SERIALIZED IN THE HTML RESUMABILITY HYDRATION VS. RESUMABILITY
73. ↝ CLIENT REDOES WORK ↝ ISLAND-LEVEL ISLANDS ↝ CLIENT DOESN'T REDO WORK ↝ SUB-COMPONENT LEVEL (SMALLER) RESUMABILITY HYDRATION VS. RESUMABILITY 🍺
74. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
75. #hotTake 🌶 Qwik is an example of the outside of the box thinking that is sometimes required on the web.
76. 🟢 STARTUP PERFORMANCE 🟢 RENDERING PERFORMANCE (ONLY CHANGED COMPONENTS NEED TO BE RE-RENDERED) 🟢 FINE-GRAINED LAZY-LOADING 🟢 PROGRESSIVE INTERACTIVITY GREAT 🟡 *PRELOAD CRITICAL PAGE INTERACTIONS 🟡 THE ONLY OPTION FOR DEVELOPERS TO LEVERAGE RESUMABILITY IS TO USE QWIK 🟡 TOO LITTLE DISCUSSION AVAILABLE ON THE IDEA NOT GREAT RESUMABILITY
77. 🟢 STARTUP PERFORMANCE 🟢 RENDERING PERFORMANCE (ONLY CHANGED COMPONENTS NEED TO BE RE-RENDERED) 🟢 FINE-GRAINED LAZY-LOADING 🟢 PROGRESSIVE INTERACTIVITY GREAT 🟡 *PRELOAD CRITICAL PAGE INTERACTIONS 🟡 THE ONLY OPTION FOR DEVELOPERS TO LEVERAGE RESUMABILITY IS TO USE QWIK 🟡 TOO LITTLE DISCUSSION AVAILABLE ON THE IDEA NOT GREAT RESUMABILITY
78. Streaming Server- Side Rendering HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! 1993 1998 2008 2017 2020 2021 2022
80. ↝ NODE STREAMS ALLOW US TO CONTINUOUSLY SEND DATA DOWN TO THE CLIENT ↝ LOAD DATA OVER A NETWORK IN MULTIPLE CHUNKS ↝ THE CHUNKS ARE LOADED OUT OF ORDER IN PARALLEL TO RENDERING STREAMING SSR
81. STREAMING SSR (BEFORE) renderToString() TRANSFER HTML RENDER TIME TO FIRST BYTE FIRST MEANINGFUL PAINT
82. STREAMING SSR (AFTER) renderToNodeStream() TRANSFER HTML RENDER TIME TO FIRST BYTE FIRST MEANINGFUL PAINT
83. #case💡 An e-commerce. Product pages have a lot of personalized content: localized description, a dynamic list of recommended products powered and a custom deals banner.
84. 🟢 FAST TIME TO FIRST BYTE (TTFB) 🟢 FASTER FIRST CONTENTFUL PAINT (FCP) AND TIME TO INTERACTIVE (TTI) 🟢 HANDLING OF BACKPRESSURE 🟢 BRIDGES THE GAP BETWEEN A PURE SSR AND A CSR EXPERIENCE GREAT 🟡 MIGRATION WASN’T ALWAYS EASY NOT GREAT STREAMING SSR
85. 🟢 FAST TIME TO FIRST BYTE (TTFB) 🟢 FASTER FIRST CONTENTFUL PAINT (FCP) AND TIME TO INTERACTIVE (TTI) 🟢 HANDLING OF BACKPRESSURE 🟢 BRIDGES THE GAP BETWEEN A PURE SSR AND A CSR EXPERIENCE GREAT 🟡 MIGRATION WASN’T ALWAYS EASY NOT GREAT STREAMING SSR
86. Selective Hydration HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! 1993 1998 2008 2017 2020 2021 2022
87. HYDRATION IN REACT (THE BAD PARTS™) FETCHING DATA (SERVER) RENDERING HTML (SERVER) LOADING CODE (CLIENT) HYDRATING TIME TO FIRST BYTE FIRST CONTENTFUL PAINT TIME TO INTERACTIVE
88. HYDRATION IN REACT (THE BAD PARTS™) ↝ HYDRATION COULD ONLY BEGIN AFTER THE ENTIRE DATA WAS FETCHED AND RENDERED ↝ USERS COULDN’T INTERACT WITH THE PAGE UNTIL HYDRATION WAS COMPLETE FOR THE WHOLE PAGE ↝ PARTS OF YOUR APP THAT LOAD FAST WOULD ALWAYS HAVE TO WAIT FOR THE SLOW ONES
89. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
90. (STREAMING SSR +) SELECTIVE HYDRATION FETCHING DATA (SERVER) RENDERING HTML (SERVER) LOADING CODE (CLIENT) HYDRATING TIME TO FIRST BYTE FIRST CONTENTFUL PAINT TIME TO INTERACTIVE
91. TIME TO FIRST BYTE FIRST CONTENTFUL PAINT TIME TO INTERACTIVE […] FETCHING DATA (SERVER) RENDERING HTML (SERVER) HYDRATING LOADING CODE (CLIENT) […] […] […] […] […] […] (STREAMING SSR +) SELECTIVE HYDRATION
92. ↝ pipeToNodeStream + createRoot + <Suspense> ↝ REACT PRIORITIZES HYDRATING THE PARTS THAT THE USER INTERACTED WITH BEFORE THE REST ↝ COMPONENTS CAN BECOME INTERACTIVE FASTER BY ALLOWING THE BROWSER TO DO OTHER WORK AT THE SAME TIME AS HYDRATION (STREAMING SSR +) SELECTIVE HYDRATION
93. ↝ REACT WON'T WAIT FOR HUGE COMPONENTS TO LOAD TO CONTINUE STREAMING HTML FOR THE REST OF THE PAGE ↝ WHEN THE HTML BECOMES AVAILABLE ON THE SERVER, IT WILL BE ADDED TO THE SAME STREAM ALONG WITH A SCRIPT TAG AND INSERTED IN THE RIGHT PLACE (STREAMING SSR +) SELECTIVE HYDRATION
94. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
95. 🟢 LOWER FIRST INPUT DELAY (FID) 🟢 LOWER INTERACTION TO NEXT PAINT (INP) GREAT NOT GREAT (STREAMING SSR +) SELECTIVE HYDRATION
96. ↝ EVENT HANDLER CREATION HAPPENS BEFORE THE EVENT IS TRIGGERED (EAGER) ↝ ALL POSSIBLE EVENT HANDLERS ARE CREATED AND REGISTERED (SPECULATIVE) ↝ CLIENT REDOES WORK ↝ REQUIRES THE FRAMEWORK TO DOWNLOAD AND EXECUTE THE COMPONENTS TO FIGURE OUT HIERARCHY HYDRATION ↝ EVENT HANDLER CREATION HAPPENS AFTER THE EVENT IS TRIGGERED (LAZY) ↝ ONLY TRIGGERED EVENTS ARE CREATED AND REGISTERED (AS-NEEDED) ↝ CLIENT DOESN'T REDO WORK (VIA DESERIALIZATION) ↝ REQUIRES ALL THE INFORMATION TO BE SERIALIZED IN THE HTML RESUMABILITY HYDRATION VS. RESUMABILITY
97. ↝ EVENT HANDLER CREATION HAPPENS BEFORE THE EVENT IS TRIGGERED (EAGER) ↝ ALL POSSIBLE EVENT HANDLERS ARE CREATED AND REGISTERED (SPECULATIVE) ↝ CLIENT REDOES WORK ↝ REQUIRES THE FRAMEWORK TO DOWNLOAD AND EXECUTE THE COMPONENTS TO FIGURE OUT HIERARCHY SELECTIVE HYDRATION ↝ EVENT HANDLER CREATION HAPPENS AFTER THE EVENT IS TRIGGERED (LAZY) ↝ ONLY TRIGGERED EVENTS ARE CREATED AND REGISTERED (AS-NEEDED) ↝ CLIENT DOESN'T REDO WORK (VIA DESERIALIZATION) ↝ REQUIRES ALL THE INFORMATION TO BE SERIALIZED IN THE HTML RESUMABILITY HYDRATION VS. RESUMABILITY
98. React Server Components HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! 1993 1998 2008 2017 2020 2021 2022
102. ↝ AHEAD-OF-TIME REACT RENDERING (DURING THE BUILD OR ON THE SERVER) ↝ A ROUTING PARADIGM ↝ INTEGRATED WITH DATA FETCHING AND BUNDLING ↝ UNRELATED TO SSR (AND HYDRATION) REACT SERVER COMPONENTS
103. ↝ ALMOST IDENTICAL TO HOW ISLANDS WORK ↝ “use client” MARKS A BOUNDARY BETWEEN TWO MODULE GRAPHS ↝ EACH COMPONENT DECIDES WHETHER TO BE A SERVER COMPONENT OR TO STICK WITH BEING A SERVER + CLIENT COMPONENT REACT SERVER COMPONENTS
104. ↝ CODE FOR SERVER COMPONENTS IS NEVER DELIVERED TO THE CLIENT ↝ ACCESS TO THE BACK-END FROM THE TREE ↝ MAY BE REFETCHED WHILE MAINTAINING CLIENT- SIDE STATE INSIDE OF THE TREE REACT SERVER COMPONENTS
105. 🟢 PURELY ADDITIVE 🟢 SMALLER BUNDLES 🟢 FASTER REHYDRATION (FEWER COMPONENTS ON THE CLIENT) GREAT 🟡 A LOT OF DATA TO SEND ALONG THE WIRE EVERY SERVER RE-RENDER 🟡 MUCH MORE ORCHESTRATION NEEDED 🟡 STILL EXPERIMENTAL 🟡 ONLY FEW OPTIONS FOR DEVELOPERS TO LEVERAGE RSC NOT GREAT REACT SERVER COMPONENTS
106. 🟢 PURELY ADDITIVE 🟢 SMALLER BUNDLES 🟢 FASTER REHYDRATION (FEWER COMPONENTS ON THE CLIENT) GREAT 🟡 A LOT OF DATA TO SEND ALONG THE WIRE EVERY SERVER RE-RENDER 🟡 MUCH MORE ORCHESTRATION NEEDED 🟡 STILL EXPERIMENTAL 🟡 ONLY FEW OPTIONS FOR DEVELOPERS TO LEVERAGE RSC NOT GREAT REACT SERVER COMPONENTS
108. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
109. < ! - - Database, file, and socket access from JavaScript - - > <script runat="server"> var resultSet = Jaxer.DB.execute("SELECT * FROM myTable"); var newPrice = resultSet.rows[0].price; </script> < ! - - Directly call server-side functions from the browser - - > <script runat="server-proxy"> function getPriceFromServer() { return 42; } </script> <button onclick="alert(getPriceFromServer())">Price</button> < ! - - Share validation code on the browser and server - - > <script runat="both"> function validateCreditCard(number) {} </script> REACT SERVER COMPONENTS (PRIOR ART)
110. < ! - - Database, file, and socket access from JavaScript - - > <script runat="server"> var resultSet = Jaxer.DB.execute("SELECT * FROM myTable"); var newPrice = resultSet.rows[0].price; </script> < ! - - Directly call server-side functions from the browser - - > <script runat="server-proxy"> function getPriceFromServer() { return 42; } </script> <button onclick="alert(getPriceFromServer())">Price</button> < ! - - Share validation code on the browser and server - - > <script runat="both"> function validateCreditCard(number) {} </script> REACT SERVER COMPONENTS (PRIOR ART)
112. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
115. REACT SERVER COMPONENTS
116. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
117. The Edge HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! 1993 1998 2008 2017 2020 2021 2022
119. #definition 🧐 Edge Functions allow you to serve content from the CDN server closest to the user. — UNDERSTANDING EDGE FUNCTIONS: THE EDGE AND BEYOND
120. THE EDGE ↝ BRINGING COMPUTING CLOSER TO THE SOURCE OF THE DATA ↝ FEWER PROCESSES IN THE CLOUD ↝ MINIMIZES THE NEED FOR LONG DISTANCE COMMUNICATIONS BETWEEN CLIENT AND SERVER ↝ REDUCES LATENCY AND BANDWIDTH USAGE
121. ↝ 🦾 IOT DEVICES ↝ 🔒 SECURITY SYSTEM MONITORING ↝ 🏥 MEDICAL MONITORING DEVICES ↝ 🚗 SELF-DRIVING CARS THE EDGE
122. 1998 2001 2006 2012 2014 2016 AKAMAI CDN PEER-TO-PEER CLOUD COMPUTING FOG COMPUTING AWS LAMBDA JAMSTACK THE EDGE: TIMELINE
123. 1998 2006 2012 2014 2016 THE EDGE: TIMELINE 2001 2017 CLOUDFLARE WORKERS
124. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
125. 1998 2006 2012 2014 2016 THE EDGE: TIMELINE 2001 2017 CLOUDFLARE WORKERS DENO VERCEL EDGE RUNTIME NETLIFY EDGE FUNCTIONS 
 2022
126. — THE FUTURE OF THE WEB IS ON THE EDGE, BY ANDY JIANG
127. THE EDGE Location Heroku TTFB Frankfurt 339.95ms Amsterdam 382.62ms London 338.09ms New York 47.55ms Dallas 144.64ms San Francisco 302ms Singapore 944.14ms Sydney 889.85ms Tokyo 672.49ms Bangalore 984.39ms — THE FUTURE OF THE WEB IS ON THE EDGE, BY ANDY JIANG
128. THE EDGE Location Heroku TTFB Deno TTFB Frankfurt 339.95ms 28.45ms Amsterdam 382.62ms 29.72ms London 338.09ms 22.3ms New York 47.55ms 41.29ms Dallas 144.64ms 29.28ms San Francisco 302ms 44.24ms Singapore 944.14ms 528.57ms Sydney 889.85ms 26.46ms Tokyo 672.49ms 19.04ms Bangalore 984.39ms 98.23ms — THE FUTURE OF THE WEB IS ON THE EDGE, BY ANDY JIANG
129. THE EDGE
130. The Future 🔮 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
131. ROUTING (& MPAs vs. SPAs)
132. HYDRATION
133. OKB JAVASCRIPT
134. (WHY) <SOMETHING> IS THE FUTURE
135. Closing Thoughts HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
136. IT ALL SOUNDS INCREDIBLY COMPLEX! WE'RE ADDRESSING THE UNCERTAINTIES OF THE MODERN WEB WHEN IT COMES TO CONNECTION QUALITY AND CLIENT DEVICE COMPUTATIONAL CAPABILITY. #1 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
137. THE SAME PATTERN CAN BE BENEFICIAL AND DETRIMENTAL IT IS ALSO QUITE LIKELY THAT DIFFERENT TYPES OF PAGES REQUIRE DIFFERENT RENDERING PATTERNS ON THE SAME WEBSITE. #2 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
138. HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
140. APPLICATION HOLOTYPES Portfolio Content Storefront Social Network I m m ersive Holotype Personal Blog CNN Amazon Facebook Figma Interactivity Minimal Linked Articles Purchase Multi-Point, Real-time Everything Session Depth Shallow Shallow Shallow - Medium Extended Deep Values Simplicity Discover-ability Load Performance Dynamicism I m m ersiveness Routing Server Server, HTML Swap HTML Swap, Hybrid Hybrid, Client Client Rendering Static Static, SSR Static, SSR SSR CSR Hydration None Progressive, Partial Partial, Resumable Any None (CSR) Frameworks 11ty Astro, Elder Marko, Qwik, Hydrogen Next, Remix Create React App — PATTERNS FOR BUILDING JAVASCRIPT WEBSITES IN 2022, BY RYAN CARNIATO
141. THE SOLUTION TO THE PROBLEM ONLY CHANGES THE PROBLEM. #3 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
142. #4 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
143. IT'S EASY TO THINK WE'RE JUST GOING BACK TO RENDERING HTML ON THE SERVER BUT THESE DAYS THE BOUNDARIES ARE VERY DIFFERENT. #4 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
146. SOFTWARE DEVELOPMENT CONTINUALLY GOES THROUGH CYCLES. WHAT'S DIFFERENT NOW? #5 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
147. THERE'S NO SILVER BULLET. IDENTIFY YOUR CORE METRICS. ALWAYS TRY TO CORRELATE BUSINESS METRICS WITH PERFORMANCE. #6 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
148. THIS IS ME, NINE YEARS AGO, GIVING A TALK ABOUT IONIC AT AN IOS DEVELOPERS MEETUP TELLING THEM THAT ANGULAR WOULD BE THE FUTURE.
149. DON'T ALWAYS TRUST SPECULATIONS AND PREDICTIONS! #7 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY!
150. THAT’S ALL, FOLKS! THANKS! 👋 🇮🇨 QUESTIONS? ↑ ALL THE LINKS! 🤓 HYDRATION, ISLANDS, STREAMING, RESUMABILITY… OH MY! MATHEUS ALBUQUERQUE • @ythecombinator