Markdown-based learning resources for developers.
DevBook is a living library of technical knowledge for developers, by developers. Every concept is explained in plain Markdown — from the mathematical foundations that power machine learning, to the networking protocols that move data across the internet, to the programming patterns that shape production-grade software.
No dependencies. No build step. No npm install. Open any .md file in your editor or browser and start reading.
Ready to begin?** Open the Master Index — your world map for the entire library. Pick a subject that calls to you and start the journey.
- Working developers brushing up on fundamentals or exploring unfamiliar territory.
- Students and career-switchers building a structured foundation in computer science and software engineering.
- AI agents tasked with generating, reviewing, or maintaining technical content.
- Anyone who prefers plain-text, distraction-free learning over video courses and interactive platforms.
21 subjects, each containing one or more modules with focused content files. Every document follows a mandatory 9-section format designed for clarity and retention.
| Subject | Directory | Scope |
|---|---|---|
| Mathematics | content/en_US/mathematics/ |
Linear algebra, calculus, probability & statistics, discrete math, number theory |
| Computer Science | content/en_US/computer-science/ |
Data structures, algorithms, OS concepts, compilers, computation theory |
| Physics | content/en_US/physics/ |
Newtonian mechanics, electromagnetism — intuition for simulation, rendering, game dev |
| Hardware | content/en_US/hardware/ |
Embedded systems, electronics, IoT, firmware, computer architecture |
| Subject | Directory | Scope |
|---|---|---|
| Programming | content/en_US/programming/ |
Language paradigms, OOP, FP, design patterns, testing, debugging, CI/CD |
| Software Engineering | content/en_US/software/ |
Methodology, testing, project management, code review, team practices |
| Systems Design | content/en_US/systems-design/ |
Scalability, consistency models, caching, CDNs, message queues, microservices |
| UI/UX Design | content/en_US/ui-ux/ |
Interface design, accessibility, interaction patterns, design systems |
| Subject | Directory | Scope |
|---|---|---|
| Networks | content/en_US/networks/ |
OSI & TCP/IP, HTTP/HTTPS, DNS, TLS, routing, load balancing, REST, gRPC |
| Security | content/en_US/security/ |
OWASP Top 10, authentication, authorization, encryption, OAuth2, JWT, CSP |
| Data & Databases | content/en_US/data-databases/ |
SQL, NoSQL, data modeling, indexing, storage engines, data pipelines |
| Cloud & DevOps | content/en_US/cloud-devops/ |
Infrastructure, CI/CD, containerization, orchestration, monitoring |
| AI / Machine Learning | content/en_US/ai-ml/ |
Neural networks, gradient descent, transformers, NLP, computer vision, MLOps |
| Subject | Directory | Scope |
|---|---|---|
| English | content/en_US/english/ |
Technical writing, documentation style, grammar, clear communication |
| Subject | Directory | Scope |
|---|---|---|
| Careers | content/en_US/careers/ |
In-depth explorations of software professions — roles, responsibilities, progression |
| Business | content/en_US/business/ |
Entrepreneurship, corporate finance, investment, business models, strategy |
| Governance | content/en_US/governance/ |
Law, policy, ethics, regulation, compliance for digital technology |
| Subject | Directory | Scope |
|---|---|---|
| Level Up | content/en_US/level-up/ |
Existential recovery, resilience, habits, meaning, and purpose |
| Philosophy | content/en_US/philosophy/ |
Existentialism, stoicism, ethics, meaning, and the good life |
| Psychology | content/en_US/psychology/ |
Positive psychology, behavioral psychology, cognitive psychology |
| Social | content/en_US/social/ |
Psychology, communication, human relations, teamwork, cognitive biases |
git clone https://github.com/reasvyn/devbook.git
cd devbook
# Open any .md file in your editor or browser — that's itNew to DevBook? Start with HOW-TO-USE.md — a practical guide to reading, navigating, and getting the most out of the library.
- Browse by subject — enter any top-level directory and open its
index.md. - Follow a learning path — each module
index.mdis a numbered learning path with phases and optional branches. - Search —
grep -r "topic" devbook/to find what you need across all subjects.
content/en_US/{subject}/
├── index.md
├── intro/ ← subject-level intro (required)
│ ├── index.md ← lists all intro files
│ └── {short-description}.md
└── {module}/
├── index.md
├── intro/ ← module-level intro (required)
│ ├── index.md ← lists all intro files
│ └── {short-description}.md
├── {short-description}.md ← content files (flat)
└── {submodule}/ ← optional
├── index.md
└── {short-description}.md
Every content file is reachable from the root through four levels of navigation:
Level 1 Master (root) /index.md
└── [Subject](subject/index.md)
Level 2 Subject subject/index.md
└── [Module](subject/module/index.md)
Level 3 Module subject/module/index.md
├── [Intro](subject/module/intro/index.md)
└── [Submodule](subject/module/submodule/index.md) (optional)
Level 4 Submodule/Intro subject/module/intro/index.md
subject/module/submodule/index.md
└── {short-description}.md
A content file is only considered published when it appears at all four levels. A missing link at any level means the content is orphaned.
The careers/ directory follows the same convention. Each career is a module that explores a profession in depth — what the role entails, its responsibilities, specializations, career progression, and industry context. These documents discuss the profession itself, not what someone should learn to enter it.
Every content file follows a mandatory 9-section structure:
| # | Section | Required | Purpose |
|---|---|---|---|
| 1 | Title | Yes | Document title |
| 2 | Description | Yes | Brief overview — what this covers and why a developer should care |
| 3 | Prerequisites | Yes | What the reader should know first, with links to related documents |
| 4 | Table of Contents | Yes | Section navigation with anchor links |
| 5 | Content / Material | Yes | Core material — explanations, code, diagrams, examples, walkthroughs |
| 6 | Learning Tips | Optional | Study advice, memory aids, practice strategies, common pitfalls |
| 7 | Glossary | Yes | Key terms and definitions introduced in the document |
| 8 | Quick References | Optional | Verified external links to journals, books, blog posts, websites |
| 9 | Next Steps | Yes | Where to go from here — related documents, practice exercises |
Sections marked "(Optional)" may be omitted if genuinely not needed. All content must be written in English using professional, technical, academic register. See CONTENT-RULES.md for the complete specification.
| Reason | Why It Matters |
|---|---|
| Zero friction | Open any .md file — no tooling, no setup, no login. |
| Git-friendly | Meaningful diffs, easy reviews, simple collaboration. |
| Universal renderer | GitHub, VS Code, Obsidian, Notion — every platform speaks Markdown. |
| Focus on substance | No styling rabbit holes; the content is the product. |
| Extensible | Embed LaTeX via $$, diagrams via Mermaid, or ASCII art. |
This repository includes AGENTS.md — a navigation hub for AI agents managing content. It points to:
- CONTENT-RULES.md — All content rules, conventions, tiering, directory structure, index system
- TEMPLATE.md — Document template with all 9 sections
- AGENTS.md — Index-First Workflow and agent skill navigation
Any AI agent working with DevBook content should read AGENTS.md before making changes.
DevBook thrives on community input. If you'd like to add or improve a topic:
- Fork the repo.
- Create a branch (
git checkout -b topic/your-topic). - Write your content in Markdown following the existing style.
- Open a pull request.
See CONTRIBUTING.md for a quick-start guide and the pull request process. See CONTENT-RULES.md for the complete rule set and TEMPLATE.md for the document format.
- HOW-TO-USE.md — practical guide to reading, navigating, and using DevBook
- AGENTS.md — AI agent navigation hub and project conventions
- CONTRIBUTING.md — contributor guidelines and contribution workflows
- CONTENT-RULES.md — content rules, conventions, and structural requirements
- TEMPLATE.md — document template and tiering guidance
- content/index.md — master language index (choose your language)
MIT — free to use, share, and adapt.
Most of the content in this repository is generated with assistance from AI.