E-Commerce Development E-Commerce Development Performance Optimization

Question 1

Which metric measures the time from when a user navigates to a page to when the largest visible content element is fully rendered?

Accepted Answer

Largest Contentful Paint (LCP)

Answer

LCP (Largest Contentful Paint) measures rendering time of the largest image or text block visible in the viewport, and Google recommends it be under 2.5 seconds for a good user experience.

Question 2

What is the purpose of a Content Delivery Network (CDN) for an e-commerce store?

Accepted Answer

To serve static assets from geographically distributed servers closest to the user

Answer

A CDN caches static assets (images, CSS, JS) on edge servers worldwide so users receive content from the nearest server, reducing latency and improving page load speed.

Question 3

Which image format is recommended for e-commerce product images to achieve the best compression with high visual quality?

Accepted Answer

WebP

Answer

WebP provides 25–35% smaller file sizes compared to JPEG and PNG at equivalent visual quality, making it the preferred format for e-commerce product images to improve load speed.

Question 4

What does 'lazy loading' mean in the context of e-commerce product images?

Accepted Answer

Deferring image loading until the image is about to enter the user's viewport

Answer

Lazy loading defers the download of images until they are about to be scrolled into view, reducing initial page load time and bandwidth usage on product listing and category pages.

Question 5

What is code splitting in the context of an e-commerce front-end built with React or Next.js?

Accepted Answer

Breaking the JavaScript bundle into smaller chunks loaded on demand per route or component

Answer

Code splitting breaks the JavaScript bundle into smaller chunks so users only download the code needed for the current page, reducing initial load time on high-traffic pages like the homepage and PDP.

E-Commerce Development Practice Test

E-Commerce Development Practice Test

E-Commerce Development E-Commerce Development Performance Optimization