React to the Need for Speed

on YouTube ↗29m

" summary

SumUp faces slow pages from bloated JavaScript so the team adds bundle-size tools and automated checks, applies code splitting + multiple webpack entries to avoid loading React on simple pages, and implements SSR + hydration (Next.js) to improve first paint but TTI still sits around ~9s. Measurements use Google Analytics + User Timing from real devices; concrete network math: 4 Mbps ≈ 500 KB/s so a 5 MB page takes ~10s; JS parse 1 MB ≈ 2s on iPhone 8, ~13–15s on mid Android.

AI-written summary · about

" chapters (15)

1. 0:00Start
2. 4:35SIDE QUESTS
3. 4:50RISE AND FALL OF EMPIRES
4. 5:00MONSTERS
5. 6:59THE STORY
6. 9:22AVERAGE CONNECTION SPEED IN BRAZIL
7. 10:17THE PERFORMANCE PERCEPTION
8. 12:01THE COST OF PROCESSING TIME IN SECONDS FOR IMB OF JAVASCRIPT
9. 13:17RAIL MODEL
10. 16:06REACT SINGLE PAGE APPLICATIONS
11. 17:48BUNDLE SIZE BUDGETS
12. 18:18CODE SPLITTING
13. 20:27MULTIPLE ENTRY POINTS
14. 22:18META-FRAMEWORKS
15. 24:50LESSONS LEARNED

" related talks

• 08mLightning fast SSR React apps with top perceived performance and no (client side) JavaScriptHåkon Gullord Krogh · React Amsterdam 2019
• 24mHoussein Djirdeh - Progressive ReactHoussein Djirdeh · React Loop 2019
• 25mDesigning High Performance React ApplicationsSendil Kumar N · JSWorld Conference 2022
• 16mNeed for Speed: How Modern JavaScript Frameworks Are Solving Web PerformanceKaleb Garner · Commit Your Code 2025
• 26mProgressive ReactHoussein Djirdeh · React Boston 2018
• 34mOptimizing Performance in Large-Scale React & Node.js ApplicationsTejas Gavankar, Hrithik Gavankar · DevConf.CZ 2025
• 32mPractical Performance Tips Building Progressive Web AppsNarendra Shetty · React Amsterdam 2017
• 26mLightning Fast React AppsSia Karamalegos · AgentConf 2018