Optimizing React Native Performance for Large Datasets

Working with large datasets in React Native can be challenging, especially when dealing with files over 300MB. Here are some key strategies I've learned from optimizing construction drawing viewers.

The Challenge

Construction workers need access to detailed drawings on job sites with poor connectivity. These drawings can be massive - often 300MB+ - and need to load quickly on older iPads.

Key Optimization Strategies

1. Compressed Data Flow

Implementing a compressed data flow system between React Native and WebView was crucial:

// Example of optimized data transfer
const compressedData = await compressDrawingData(largeDrawing);
webViewRef.current.postMessage({
  type: 'DRAWING_DATA',
  data: compressedData,
  compression: 'gzip'
});

2. Virtualization for Large Lists

When displaying thousands of drawing elements, virtualization is essential:

import { VirtualizedList } from 'react-native';

const DrawingList = ({ drawings }) => (
  <VirtualizedList
    data={drawings}
    renderItem={({ item })=> <DrawingItem drawing={item} />}
    getItemCount={(data) => data.length}
    getItem={(data, index) => data[index]}
    initialNumToRender={10}
    maxToRenderPerBatch={10}
    windowSize={5}
  />
);

3. Memoization Strategies

Heavy computations need to be memoized:

import { useMemo } from 'react';

const ProcessedDrawing = ({ drawingData }) => {
  const processedData = useMemo(() => {
    return processDrawingData(drawingData);
  }, [drawingData]);

  return <DrawingViewer data={processedData} />;
};

Results

These optimizations resulted in:

• 60% faster load times
• Reduced crashes on older devices
• Improved user experience in poor connectivity areas

The key is understanding your specific use case and optimizing accordingly. For construction apps, offline-first architecture combined with smart caching strategies makes all the difference.