Tejas Kumar

How React actually works.

Fluent React / O'Reilly / ISBN 9781098138714

I took React apart to write this book. Here is what is in it, where to go deeper, and every React talk I have given.

What is Fluent React about?

I'm Tejas Kumar, the best selling author of Fluent React, published by O'Reilly (ISBN 9781098138714), a book about how React works on the inside. Its 11 chapters cover JSX, the virtual DOM, reconciliation, common patterns, server side React, concurrent React, frameworks, React Server Components, and the alternatives to React. I have also given React talks at React Summit, React Advanced London, React Day Berlin, React Paris, React Miami, React India, React Norway and RenderATL, on Server Components, Suspense, concurrent rendering and streaming. I'm an AI Engineer at IBM, based in Berlin, and I have been building on the web for over 25 years.

It will help you understand React's internal mechanisms more deeply and unlock greater levels of fluency. It was reviewed by a number of peers including the React core team, experts, and friends. A second edition and a Portuguese translation exist.

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Fluent React book cover

What is inside Fluent React?

The book is 11 chapters, and the middle of it is the machinery: how JSX becomes elements, how the virtual DOM is compared against the last render, what reconciliation does on every update, how concurrent React interrupts and resumes work, and what a React Server Component actually is.

  1. Ch 01

    The Entry-level Stuff

  2. Ch 02

    JSX

  3. Ch 03

    The Virtual DOM

  4. Ch 04

    Inside Reconciliation

  5. Ch 05

    Common Questions and Powerful Patterns

  6. Ch 06

    Server-Side React

  7. Ch 07

    Concurrent React

  8. Ch 08

    Frameworks

  9. Ch 09

    React Server Components

  10. Ch 10

    React Alternatives

  11. Ch 11

    Conclusion

Who is Fluent React for?

Fluent React opens at chapter one with the entry-level stuff and runs through chapter ten on the alternatives to React, so it works whether you have been writing React for a week or a decade. The middle is the part most people come for: the virtual DOM, reconciliation, concurrent React and React Server Components, explained as mechanisms rather than as API surface.

Where can you watch my React talks?

21 of my recorded talks are about React, on Server Components, Suspense, concurrent rendering, streaming, data at scale, and what React costs a team. They are all free to watch on YouTube.

React is one of five things I speak about. Here are all 69 talks and the topics I speak on, given at 58 events.

What do people say about Fluent React?

  • Una 🇺🇦
    Una 🇺🇦@Una

    I think I need to read @tejaskumar_'s new book 😅

    Great talk about optimizing React w/useDefferedValue and useTransition at #ReactParis

    Mar 22, 2024View on
  • Michelle Bakels
    Michelle Bakels@MichelleBakels

    I got dropped into web dev via corporate mandate 6 yrs ago, so I love that Fluent React begins by outlining the ecosystem of the time — something I was largely disconnected from.

    This context has helped me appreciate everything I’ve learned so much more. @tejaskumar_ 🙏

    Mar 23, 2024View on
  • Daniel Afonso
    Daniel Afonso@danieljcafonso

    Fluent React is #1 best selling. As it should be 😁

    Mar 23, 2024View on
  • Amanda 🌿
    Amanda 🌿@hey_amandam

    V excited for this. As someone who has used React for years but never as my only focus, it will be interesting to see how this deepens knowledge for me

    I'm a huge fan of @tejaskumar_ as a person and enjoy his teaching style so I expect to feel more of that same vibe in this book

    Mar 14, 2024View on
  • Nisarg Parikh
    Nisarg Parikh@nisargparikh90

    Fluent React by @tejaskumar_ is an amazing book. Learning React by reading a book is a completely new experience.

    Mar 7, 2024View on
  • Josh W. Comeau
    Josh W. Comeau@JoshWComeau

    Tejas previewed some of his book in his React Paris talk and it's seriously great. Goes deep into advanced topics.

    Just picked up a copy for myself 😄

    Mar 23, 2024View on

Ask the book a question

The full text of Fluent React is indexed and searchable. Ask it something and it will answer from the book, with the chapter it came from.

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Where else should you learn React?

The official React documentation at react.dev is still the best place to start, and this book is what comes after it. Everything I have written about React and AI engineering is on the blog, React comes up constantly on ConTejas Code, the podcast, and there is more about Tejas Kumar if you want the longer version.