Books for developers

The standard first textbook for statistical learning, free as a PDF in two editions: ISLR2 with R labs and ISLP with Python labs. It explains regression, classification, resampling, regularisation, trees, SVMs, deep learning and unsupervised learning with the minimum of maths, and ends every chapter with a hands-on lab.

• AI
• Machine learning
• Programming

A free, full-length book by freeCodeCamp's founder, written for people learning to code on their own, often while working another job. It treats getting hired as three parallel efforts: skills, a network and a reputation, which is exactly the shape a career switch needs.

• Career
• Job search

A free online book that walks you through building two complete interpreters for a small scripting language, one in Java and one in C, explaining scanning, parsing, evaluation, bytecode, virtual machines and garbage collection along the way. It is the friendliest route to understanding how programming languages work.

• Programming
• CS fundamentals

A widely used operating systems textbook from the University of Wisconsin-Madison, free to read chapter by chapter online. It is organised around three ideas, virtualisation, concurrency and persistence, and written in a friendly, question-driven style with homework simulators and projects. It is the best free way to understand processes, scheduling, virtual memory, locks and file systems.

• CS fundamentals

An O'Reilly book from 2020 by Titus Winters, Tom Manshreck and Hyrum Wright on how Google keeps an enormous codebase healthy over time: team culture, code review, documentation, testing at scale, deprecation, dependency management, large-scale changes and continuous delivery. The full text is free to read online. Most rewarding after a year or two of professional work, when the problems it describes start to look familiar.

• Career
• Programming
• Testing
• Leadership

A free book by Ryan Singer of Basecamp on how its product teams work: shaping a project before committing to it, betting on it with a fixed time budget of up to six weeks, and letting the team cut scope to ship on time. Even if your company never adopts the method, the chapters on shaping, appetite and scope mapping change how you plan and scope your own projects.

• Career
• Leadership

William Shotts' book on the Linux shell, free to download as a PDF under a Creative Commons licence and published in print by No Starch Press. It covers navigation, permissions, processes, package management, text processing, regular expressions and writing real shell scripts. It is the thorough reference to reach for when lecture notes and cheat sheets leave gaps, and suits beginners and self-taught developers alike.

• DevOps
• Dev tools

Chip Huyen's 2022 O'Reilly book on everything around the model: business framing, data engineering, training data, feature engineering, evaluation, deployment, distribution shift, monitoring, continual learning and MLOps infrastructure. It explains why models that score well in a notebook fail months after launch. It is for ML engineers, data scientists and engineers moving into ML who need to build systems that keep working in production.

• AI
• Machine learning
• System design
• DevOps

A modern deep learning textbook by Simon J.D. Prince, published by MIT Press in 2023 and free to download as a PDF. It explains how networks, transformers, diffusion models and reinforcement learning actually work, with clear figures and Python notebooks for every chapter. It suits students and engineers who can run a model but want to understand why it works, without a dense research-level text.

• AI
• Machine learning

A 2020 Cambridge University Press textbook by Marc Peter Deisenroth, A. Aldo Faisal and Cheng Soon Ong, free as a PDF. It covers linear algebra, analytic geometry, matrix decompositions, vector calculus, probability and optimisation, then applies them to linear regression, PCA, Gaussian mixture models and support vector machines. It is for students who want to know exactly why ML methods work, and are ready for more rigour than a video course.

• AI
• Machine learning
• CS fundamentals

The book on data wrangling in Python by Wes McKinney, the creator of pandas. The third edition (O'Reilly, 2022) is updated for pandas 2.0 and Python 3.10 and is free to read online, covering NumPy, pandas, cleaning, reshaping, grouping, time series and plotting. It suits students and engineers who want to become fluent at loading and shaping real data before moving on to machine learning.

• AI
• Programming
• Machine learning

A free online book by Al Sweigart, now in its third edition, that teaches Python through practical scripts: organising files, working with spreadsheets, PDFs and Word documents, scraping websites, sending email and controlling the keyboard and mouse. It assumes no programming experience and suits beginners and office workers who want to automate real tasks, as well as developers looking for small, useful project ideas.

• Programming

The official Git book by Scott Chacon and Ben Straub, free online and as PDF or EPUB, in many languages. It covers everyday use, branching, remotes, collaboration workflows and GitHub, then the internals that explain why Git behaves the way it does. Read the basics and branching chapters for daily work, then chapter ten on internals, and Git stops being frightening.

• Dev tools

Eloquent JavaScript by Marijn Haverbeke is a book that teaches programming through JavaScript, now in its fourth edition (2024). It covers the language, the browser and Node.js, with four project chapters and exercises you can run in the page. It is free to read online, with a paper edition from No Starch Press. It suits people who can already write some code and want to think and write like a programmer, not just learn syntax.

• Web
• Programming
• CS fundamentals

Chip Huyen's O'Reilly book on building applications with foundation models such as LLMs, covering evaluation, prompt engineering, retrieval and agents, fine-tuning, dataset engineering, inference optimisation and system architecture. It is for engineers, data scientists and technical product managers who are moving an AI feature beyond the demo stage. It focuses on lasting fundamentals and decision-making rather than specific tools or code.

• AI
• Machine learning
• System design

The book that defined site reliability engineering, written by Google engineers and published by O'Reilly in 2016, and free to read online. It covers service level objectives and error budgets, eliminating toil, monitoring, release engineering, on-call, incident response, blameless postmortems, load balancing and cascading failures. It suits backend, DevOps and platform engineers who want to understand what running large production systems really involves.

• System design
• DevOps
• Cloud

The classic textbook on how search engines work, by Manning, Raghavan and Schutze, with the full text free to read online. Inverted indexes, tokenisation, scoring, tf-idf and evaluation explained from first principles.

• CS fundamentals
• DSA

Robin Williams' widely used introduction to design for people without design training, built around four principles: contrast, repetition, alignment and proximity. Short, visual and practical, it explains why layouts look clean or messy, and how to fix them.

Luca Palmieri's book on backend development in Rust: you build a real email newsletter API from scratch with integration tests, structured logging, error handling, authentication, CI and deployment. The best end-to-end picture of a production Rust service.

• Web
• Backend
• Testing
• DevOps

The practical guide to A/B testing from experimentation leaders at Microsoft, Google and LinkedIn. It covers choosing metrics, designing experiments, spotting untrustworthy results and building an experimentation platform, drawn from companies that each run more than 20,000 experiments a year.

• Data

Allen B. Downey teaches probability and statistics to Python programmers through code instead of formulas, using real datasets. The third edition is free online as Jupyter notebooks that run on Colab, so you can explore distributions, estimation, hypothesis tests and regression without installing anything.

• Programming

Google's hands-on companion to the original SRE book: how to actually implement SLOs, alert on them, run on-call, respond to incidents and write blameless postmortems, with case studies from companies outside Google. Free to read online, and the most practical single book on running reliable services.

• System design
• DevOps
• Backend
• Cloud

The official Rust book, free to read online and usually called simply "the book". It teaches ownership, borrowing, enums, error handling, traits, generics, closures, concurrency and async in a sensible order, with small projects along the way. Start here before any web framework.

• Backend
• CS fundamentals

Barbara Minto's classic method for answer-first writing: put your main point at the top, then group the supporting ideas beneath it. It turns long engineering explanations into documents executives actually read, which is exactly what customer-facing engineers need.

• Career