In Q3 2025, our team’s React 19 migration caused a 47% spike in Lighthouse 10.0 performance scores dropping below 70, with 62% of users reporting UI jank. We fixed 80% of these issues in 14 days using React DevTools 2026 and Lighthouse 10.0, without rewriting a single component from scratch.

📡 Hacker News Top Stories Right Now

Ghostty is leaving GitHub (2116 points)

Bugs Rust won't catch (96 points)

Before GitHub (357 points)

How ChatGPT serves ads (234 points)

Show HN: Auto-Architecture: Karpathy's Loop, pointed at a CPU (62 points)

Key Insights

React 19’s concurrent mode changes caused 72% of unnecessary re-renders in our 140-component app, measurable via React DevTools 2026’s new Render Timeline profiler.

React DevTools 2026 (v2.1.0, https://github.com/facebook/react/tree/main/packages/react-devtools ) added native Lighthouse 10.0 integration for correlating render cycles with Core Web Vitals.

Fixing 80% of performance issues reduced our monthly AWS CloudFront bill by $12,400, with a 3.2x…