The Day I Learned What Actually Slows Down React Apps

Every React developer thinks performance issues come from the backend—until they learn the truth.

I learned mine in the middle of a sprint where the backend team kept saying, “API is fast… the UI isn’t.”

They were right.

The Moment of Reali…


This content originally appeared on DEV Community and was authored by Nitin Nair

Every React developer thinks performance issues come from the backend—until they learn the truth.

I learned mine in the middle of a sprint where the backend team kept saying, “API is fast… the UI isn’t.”

They were right.

The Moment of Realization

A junior dev pinged me:

“Why does our UI freeze if the API is super fast?”

I opened the Profiler.

One component—just one—was re-rendering 19 times for one change.

We didn’t have a slow API.
We had unnecessary work.

The Fix

We applied:

  • React.memo for components with stable props
  • Debounced handlers
  • Avoided object spreading
  • Lazy loading
  • Bundle splitting

The fix wasn't magic. It was discipline.

The Result

32% faster load.
Smoother UI.
A happier team.

Takeaway

React performance isn’t about doing “more”. It’s about avoiding the unnecessary.


This content originally appeared on DEV Community and was authored by Nitin Nair


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