LESSON 1.3
Finding wasted renders
Learn key techniques and workflows in React Performance Engineering.
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Overview
Most React slowness is a subtree re-rendering for no reason. Track it back to the prop or context value that changes identity on every render.
In this lesson you will:
- Trace a re-render back to the prop that changed
- Spot object and function props recreated each render
- Recognise context as a re-render broadcast
Pro Tip
Use caching and revalidation wisely to ensure your app stays fast and data remains fresh without unnecessary requests.