Second edition with machine learning, deep learning, LLMs & AI available now! Buy now

The CS degree you never got

A complete introduction to computer science for self-taught developers.

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Written by Tom Johnson
Senior software engineer in FAANG

★ 4.5 stars on Amazon

Sound familiar?

The problem is that you don’t know what you don’t know.

This book fixes that. It gives you the fundamental building blocks you need to succeed.

I know the feeling. I once brought down a system during a busy sales period because I didn’t know what a file handle was. Turns out you can run out of them and crash the system!

I spent five years reading textbooks and watching lectures to fill my own knowledge gaps, then turned the useful parts into a practical map for working developers.

Incredibly helpful for building the missing foundations behind highly abstracted systems.”

Kelven Opoku, backend engineer in Big Tech

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  • ⭐ 4.5 stars on Amazon

The Computer Science Book: For Self-Taught Developers

Learn the computer science fundamentals from logic gates to LLMs

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The building blocks you need

The Computer Science Book is a guided, opinionated walk through the core areas of a computer science degree. It’s aimed at anyone who needs a practical understanding of computer science fundamentals.

This is not a thousand-page reference manual. It is a curated introduction to the parts of computer science that working developers actually need to know.

You’ll build intuition across thirteen chapters ranging from the logical foundations to the bleeding edge of AI research:

Each chapter builds up an intuitive understanding of the most important topics. You’ll map out the territory and understand how everything fits together.

When you want to go deeper, comprehensive Further Reading sections signpost more advanced topics and resources.

Adrian Booth
An essential read for anyone who felt they missed out on a CS education. The further reading sections are full of curated resources to explore each topic more deeply. Tom distils each topic beautifully and succinctly. A joy to read.

Adrian Booth

Software engineer at Syft

John Whiles
Covers all the topics I lacked confidence in. Now I feel like I have a solid base to start from if I need to dive deeper. I’ve been able to apply the content to my day-to-day work. I really recommend this book.

John Whiles

Software engineer at Contentful

New in V2

Three new chapters for the age of machine learning

The second edition extends the systems foundation with a practical map of modern AI.

You still need the old fundamentals. But now you also need enough context to place machine learning and LLMs inside the rest of computer science.

11

Machine Learning

From linear regression to unsupervised learning, building the intuition you need to understand the statistical, data-driven approach to programming.

12

Deep Learning

A deep dive into how modern neural networks learn from images, text, and sequences, and where their power actually comes from. Includes generative techniques like Stable Diffusion.

13

Large Language Models and AI

Goes from tokenisation and transformer architectures, through reinforcement learning at mid-training right up to the bleeding edge of interpretability, world models and robotic agents.

Buy the ebook - $29

Paperback and hardback are available on Amazon.

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About the author

Tom Johnson is a senior software engineer who has worked across startups, investment banks, and now Big Tech.

He took the self-taught path: Founders & Coders bootcamp in London, then years of learning on the job, plugging his knowledge gaps the hard way through textbooks, lectures, and the occasional production mistake.

The Computer Science Book is the map he wishes he’d had when he was already writing software, but still missing the deeper models underneath it.

Free Articles & Tutorials

Deep dives into CS topics that complement the book.

How NAT traversal powers video calls

You're behind NAT. Your colleague is behind NAT. Neither has a public IP. So how does video data flow directly between you? A pugilistic account of STUN, hole punching, and a clever fallback called TURN.

How interrupt handlers work

Press a key and your CPU jumps to attention. It saves everything it was doing, handles your keypress, then resumes exactly where it left off. This is how hardware demands attention.

What is an API?

One of the joys of studying computer science is spotting a familiar concept in new surroundings. It’s a wonderful “aha!” moment as …

If you have any questions, please feel free to get in touch: tom@thecomputersciencebook.com.

You can also find me on Github or on Twitter.