Taming React Renders in Heavy Dashboards

The Bottleneck

The client's primary analytics dashboard contained 12 charts. Updating a single global date filter caused all 12 charts to unmount and remount, freezing the browser for nearly 2 seconds.

The Fix

1. Context Splitting: Separated the global state into UI_Context and Data_Context.
2. useMemo & React.memo: Wrapped expensive chart components to ensure they only re-rendered when their specific data slice changed.
3. Web Workers: Offloaded the heavy JSON data parsing to a background worker.

The Outcome

Achieved a buttery-smooth 60fps interaction rate, even when processing arrays with 50,000+ data points.