A React app doesn't become slow overnight. It becomes slow when unnecessary render accumulates overtime.
A render is React running a component again to determine what should appear on the screen.
Most developers reach for
useMemo, useCallback, or another optimization as soon as performance drops. That's often treating the symptom.The better question is:
Why did this component render in the first place?
Open React DevTools and enable Highlight updates. Click around your app.
If your navigation bar flashes every time you type into a search box, you've already found a performance issue.