Optimization Performance (React/TypeScript) as Senior Front-End Engineers

React smarter; not harder. Lessons I learned at Apple.

Optimizing application performance isn’t just another skill — it’s the hallmark of a great JavaScript and React developer. Early in my career, I found myself doing the same thing repeatedly: implementing UI logic with different requirements but learning little in the process. At the time, I thought I was growing, but in hindsight, I was simply staying afloat.

What changed? A conscious decision to prioritize optimization and scalability. This wasn’t a lesson I learned overnight — it was honed through countless projects, debugging marathons, and a thirst to deliver better results. Here’s what I’ve picked up along the way, from scrappy startups to my time at Apple.

Thoughtfully Leveraging useCallback and useMemo

I still remember the first time I realized I was unintentionally causing unnecessary re-renders in a React app. It wasn’t massive, but it compounded into a laggy UI as more data was added. That’s when I fell in love with useCallback and useMemo.

Here’s how I used useCallback to optimize a counter component:

import React, { useState, useCallback } from "react";

const…