How Walmart Implements Infinite Scrolling Efficiently
Original post Implementing Infinite Scrolling Efficiently
Article Summary
Phong Lam from Walmart Global Tech tackles a problem every mobile dev faces: infinite scroll that doesn't tank performance. His solution? Stop rendering everything and start being strategic.
Infinite scrolling seems simple until you're rendering thousands of DOM nodes and watching your app crawl. Lam breaks down why the naive approach fails and presents a windowing technique that only renders what users actually see, dramatically reducing memory overhead.
Key Takeaways
- Traditional infinite scroll creates hundreds or thousands of DOM nodes
- Windowing technique renders only visible items plus small buffer
- Dynamically adjusts container height and repositions items on scroll
- Reduces interaction cost by eliminating pagination clicks on mobile
Efficient infinite scroll means rendering only what's visible while faking the rest with dynamic height calculations.
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What This Article Covers
When you try to display large lists like Twitter feeds with hundreds or thousands of items, you end up creating way too many DOM nodes. This tanks performance and makes the app basically impossible to render.
Phong Lam's windowing technique only renders the items you can actually see on screen, plus a small buffer around them. The rest of the scrollable container is faked using height calculations.
This cuts down on memory usage and interaction costs since you don't need pagination clicks on mobile anymore. You get smooth infinite scroll without the performance problems.
This page summarizes “Implementing Infinite Scrolling Efficiently” by Walmart, published Apr 2, 2019. All credit for the original work goes to the authors.
