What and Why Next.js

Developers often begin their journey by building client-side applications with React. As those applications scale, they encounter common challenges, the kind that Next.js is built to solve.

To fully understand Next.js, it’s helpful to view it not as a replacement for React but as a framework that supports React in production environments. It takes the powerful component model developers already know and builds a robust, feature-packed structure around it to handle routing, rendering, and full stack capabilities in a single, cohesive environment.

The problems Next.js solves

To understand why Next.js matters, it helps to understand how single-page applications render. In client-side React apps, most of the rendering work happens in the user’s browser. This approach supports rich interactivity but comes with two major trade-offs:

1. Slow initial loads: The browser first receives a nearly blank HTML file. It must then download, parse, and execute a potentially large JavaScript bundle before any meaningful UI can be rendered, often leaving users staring at a loading spinner.

2. Poor SEO: Search engine crawlers frequently see the same blank page, which makes it difficult to index the site’s content effectively and can negatively impact search rankings.

Next.js fundamentally solves these issues through prerendering. Instead of sending an empty file, the server sends a fully-formed HTML page. This allows the browser to display meaningful content almost instantly, significantly improving both user experience and SEO.

Modern production advantages

With the advances introduced in React 19, Next.js remains the framework of choice for production teams. Its architecture is designed to support performance, flexibility, and operational simplicity at scale. This is why leading technology companies like Hulu, Twitch, and TikTok trust it for their demanding production environments.

• Fast performance: Next.js is designed for speed. It automatically handles important performance optimizations, such as code splitting, so users only download the JavaScript needed for the page they are viewing. Features like the built-in next/image component and intelligent route prefetching further reduce load times and help deliver a fast, smooth experience.

• Flexible rendering strategies: A key strength of Next.js is that it does not force a single rendering model. Developers can choose the most appropriate rendering strategy per page.

• Full stack in one place: With built-in support for creating backend logic via Route Handlers (API routes) and Server Actions, the entire stack can be developed inside a single Next.js project. This unified approach simplifies the architecture and removes the need for a separate server.

• Built and hosted by Vercel: Because Vercel created Next.js, its cloud platform is tailored specifically for it. This tight integration makes deployment simple, often requiring only a git push. The Vercel platform automatically handles scaling, serverless functions, and global distribution via its edge network.

Better developer experience

Beyond its core capabilities, Next.js is designed to be productive and enjoyable to work with. It comes preconfigured with a modern toolchain:

• TypeScript: New projects can be initialized with built-in TypeScript support, enabling robust, type-safe code from the start.

• ESLint: Integrated linting helps catch common errors early and maintain a consistent, high-quality codebase across teams.

• Fast Refresh: It is a development-time feature that provides instant feedback in the browser upon saving code changes, without losing component state.

Who this course is for

This course is designed for junior software engineers with experience in React. A solid comfort level with React hooks (like useState, useEffect, and useContext) and component-based architecture will be enough to confidently follow the concepts we’ll cover.