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By Addy Osmani and Hassan Djirdeh

Code Smart, Scale Fast, Conquer Challenges

Learn tools and techniques to build and maintain large-scale React web applications.

Or  for free.
Building Large Scale Web Apps: A React Field Guide. By Addy Osmani and Hassan Djirdeh

“Building Large Scale Web Apps” is a toolkit to managing large-scale React applications.

React as a library allows you to start building user interfaces quickly and easily. But how do things scale as an application grows? How do you ensure that your codebase remains manageable, your performance metrics stay on point, and your team continues to work cohesively as the project evolves?

In this book, you'll uncover strategies that industry professionals use to build scalable, performant, and maintainable React applications, all without becoming overwhelmed by complexity.

Together, we've spent well over two decades building within or consulting for

The Google logo.
The Doordash logo.
The Instacart logo.
The Netflix logo.
The X logo.
The YouTube logo.
The Shopify logo.
The Ebay logo.

What's inside?

Every topic below is a chapter of its own!

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Managing Software Complexity
  • Explaining Complexity
  • Root causes of complexity
  • A philosophy of software design
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  • Modules in JavaScript
  • Lazy-loading
  • Code-splitting
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  • Understanding how browsers work
  • Reducing the cost of JavaScript
  • Rendering patterns
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Design Systems
  • Coding style guides
  • Design tokens
  • Component libraries
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Data Fetching
  • Browser APIs and simple HTTP clients
  • Advanced data-fetching libraries
  • Tips for efficient data-fetching
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State Management
  • Managing data between components
  • Simple state management
  • Dedicated state management libraries
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  • Third-party localization libraries
  • Format dates, times, and numbers
  • Right-to-left (RTL) languages
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Organizing code
  • Folder and file structure
  • Naming conventions
  • Barrel exports
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Personalization & A/B testing
  • Personalization
  • A/B Testing
  • Feature flags
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Scalable web architecture
  • Scalable applications
  • Kubernetes & Docker
  • Vercel & Netlify
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  • Unit, integration, and end-to-end tests
  • Snapshot testing
  • How should we test our apps?
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  • Version control & CI
  • Bundlers
  • Logging & performance monitoring
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Technical migrations
  • Different migration strategies
  • Codemods
  • The role of generative AI
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  • React & TypeScript
  • Autogenerating types from an API
  • Migrating a React app to TypeScript

Some other things!

Descriptive content, continous updates, and soundbites from industry professionals.

Descriptive, not prescriptive

When explaining content, we follow a descriptive approach, not prescriptive. In other words, we don’t tell you what specific tools or libraries you have to use to be successful. Rather, we focus on explaining a concept and employ certain libraries or tools to illustrate that concept.

React-focused with universal concepts

While the book is React-focused, it teaches universal concepts that transcend all web development frameworks. It's designed to enhance your understanding of building web applications that are scalable, maintainable, and adaptable, regardless of the specific technology stack.

Continous, frequent updates

Purchasing the e-book gives you access to all new content, edits, and improvements forever. In fact, we're currently working on adding three new chapters soon — Routing, User-centric API design, and React in 2024. Check out the Changelog to follow along on all the updates we'll make.

Soundbites from industry professionals

In the book, we share soundbites and thoughts from industry professionals. These soundbites are shared from start-up owners and software engineers who work at Doordash, Netflix, Spotify, and more.

Back cover of physical book
Front cover of physical book
Back cover of physical book
Contents of physical book

Industry nuggets

Nuggets of wisdom from industry professionals

Jem Young

Maxi Ferreira

Emma Bostian

Zeno Rocha

Francine Navarro

Jeffrey Peng

And others!

In my years at Netflix, I've learned a lot about testing. It's not just about the code, it's about the culture as well.

Besides the cultural aspect is the need to have a cohesive tool set. When I first joined [my team at Netflix], we had unit tests that were all over the place. We had Jest, we had Mocha, I think we had some Enzyme tests too. Now, we've kind of unified on a standard set of way of writing tests

Jem Young

Engineering Manager @ Netflix & Co-host of Front End Happy Hour.

Who we are

Heyo! We're Addy & Hassan — Engineers & Educators.

Profile picture of Addy Osmani

Addy Osmani

I'm an engineering leader working on Google Chrome and I lead up Chrome's Developer Experience organization, helping reduce the friction for developers to build great user experiences.

Hassan Djirdeh

I'm a senior software engineer and have built large production web applications at organizations like Doordash, Instacart, and Shopify.

Profile picture of Addy Osmani

Pick your package

“Building Large Scale Web Apps” is available in either an e-book or as a physical copy.


Great for digital learners.


  • 300+ pages
  • PDF or EPub (or both)
  • All future updates
Buy with Leanpub Or buy with Apple Books or Google Play

Physical copy (softcover)

Perfect for hands-on referencers.


  • 300+ pages
  • Softcover
  • Something to put on your bookshelf
  • Interested in both the e-book and physical copy? Purchase both separately!
Buy Physical Copy

Some words from readers

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