Infinite Scrolling for List Data

🚀 Project Overview

This project demonstrates a production-ready infinite scrolling system for rendering large lists efficiently. It uses IntersectionObserver to load data progressively as the user scrolls, minimizing API calls and improving performance.

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🎯 Problem Statement

Traditional pagination breaks user flow when browsing large datasets. The goal was to:

• Load data incrementally
• Avoid unnecessary re-renders
• Prevent duplicate API calls
• Keep the UI smooth on low-end devices

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🛠️ Tech Stack

• React – UI rendering
• TypeScript – Type safety
• IntersectionObserver API – Scroll detection
• Zustand – State management
• REST API – Backend pagination

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🧩 Architecture

Data Flow

1. Initial page loads first set of items
2. A sentinel element is observed at the bottom
3. When visible, next page is fetched
4. Data is appended (not replaced)
5. Observer pauses when no more pages exist

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💡 Key Implementation Details

Intersection Observer Setup

const observer = new IntersectionObserver((entries) => {
  if (entries[0].isIntersecting && hasNextPage) {
    loadNextPage();
  }
});