Start Here

Not sure what to learn first? Start with Foundations, then pick the field that excites you most. Each track goes from beginner to advanced — work through the steps in order.

Steps marked “Coming soon” are tutorials I'm still writing — the roadmap shows where each one will fit.

Foundations

9 of 9 ready

The first steps every developer needs, whatever field you choose next.

  1. Beginner

    How Computers Work

    CPU, RAM vs storage, files, processes, threads, and what the operating system actually does — the ground every other tutorial stands on.

    Start tutorial· 10 Chapters

  2. Beginner

    Command Line Basics

    Move around files, run programs, chain commands together, and stop being afraid of the terminal — every other tutorial assumes this.

    Start tutorial· 11 Chapters

  3. Beginner

    Git & GitHub for Beginners

    Save your work, undo mistakes, use branches, fix merge conflicts, and collaborate with pull requests — the first tool every company expects you to know.

    Start tutorial· 11 Chapters

  4. Beginner

    How the Web Works

    URLs, DNS, HTTP, status codes, cookies, and caching — what actually happens between typing an address and seeing a page, traced with your browser's DevTools and curl.

    Start tutorial· 11 Chapters

  5. Beginner

    HTML & CSS Fundamentals

    Structure a page with semantic HTML, style it with CSS, and make it look good on phones with the box model, Flexbox, Grid, and responsive design — then publish it.

    Start tutorial· 11 Chapters

  6. Beginner

    JavaScript & TypeScript Fundamentals

    Learn variables, functions, arrays and objects, the DOM, async code, and then add TypeScript types — and use them to make a profile page interactive.

    Start tutorial· 12 Chapters

  7. Beginner

    Math for Programmers

    Binary and hex, bitwise flags, boolean logic, sets, modulo, Big-O, counting, probability, and geometry — the everyday math hiding inside your code, learned by building a small toolkit.

    Start tutorial· 12 Chapters

  8. Intermediate

    Data Structures & Algorithms

    Arrays, hash maps, linked lists, stacks, queues, recursion, searching, sorting, trees, heaps, graphs, and dynamic programming in TypeScript — tied to where you meet them at work, and ready for technical interviews.

    Start tutorial· 14 Chapters

  9. Beginner

    SQL & Relational Databases

    Tables, keys, relationships, JOINs, aggregation, normalization, indexes, and transactions in PostgreSQL — learned by building the database of a small online shop.

    Start tutorial· 12 Chapters

Frontend

0 of 5 ready

Build the websites and web apps people actually see and click — React, Next.js, and shipping them fast.

  1. BeginnerComing soon

    React Fundamentals

    Components, props, state, and events — build interfaces out of small, reusable pieces.

  2. IntermediateComing soon

    Building Apps with Next.js

    Routing, layouts, and server vs client components — the framework this very site is built with.

  3. IntermediateComing soon

    Data Fetching & State Management

    Call your own API, handle loading and error states, build forms, and know when you actually need global state.

  4. IntermediateComing soon

    Testing Your Frontend

    Test components the way users use them, mock API calls, and catch broken flows with end-to-end tests before your users do.

  5. AdvancedComing soon

    Performance, SEO & Deployment

    Make pages load fast, get found on Google, and ship your frontend to production.

Backend & DevOps

5 of 11 ready

Build APIs, secure them, take payments, and ship them to production.

  1. Beginner

    NestJS Crash Course

    Build a Task Management REST API in 1 hour with NestJS, PostgreSQL, and Prisma.

    Start tutorial· 9 Chapters

  2. IntermediateComing soon

    Testing Your Backend

    Unit tests, integration tests against a real database, and end-to-end API tests — so you can change code without fear of breaking it.

  3. Beginner

    Docker CLI Tutorial

    Learn Docker from the CLI up — images, containers, volumes, networking, Compose, and shipping a real multi-container app to production.

    Start tutorial· 21 Chapters

  4. IntermediateComing soon

    Networking for Developers

    IP addresses and ports, TCP vs UDP, localhost vs 0.0.0.0, firewalls, TLS, and reverse proxies — plus ping, curl, and dig to debug when your app can't be reached.

  5. Beginner

    Cloud+ Tutorial

    A beginner-friendly walkthrough of Sabay's Cloud+ business services (SabayTEKH PaaS) — deploying a container with Run App, storing files with S3-compatible Storage, and running a managed Database with backups.

    Start tutorial· 10 Chapters

  6. Intermediate

    Keycloak Crash Course

    OAuth 2.0, OpenID Connect, and JWTs in about an hour — run Keycloak locally, build a realm and client by hand, decode a real access token, and protect a NestJS API with it.

    Start tutorial· 8 Chapters

  7. Accept Payments in Cambodia

    Pick one
    Intermediate

    ABA PayWay Tutorial

    A full hosted checkout — cards, ABA Pay, callbacks, and refunds.

    7 Chapters

    Intermediate

    Bakong KHQR Tutorial

    One QR code any Cambodian banking app can scan — the simplest way to get paid.

    4 Chapters

  8. IntermediateComing soon

    Caching with Redis

    Make slow endpoints fast, and learn when caching causes more problems than it solves.

  9. AdvancedComing soon

    Message Queues with RabbitMQ

    Move slow work out of the request, and let services talk without waiting on each other.

  10. AdvancedComing soon

    CI/CD Pipelines

    Test and deploy automatically on every push, so shipping becomes boring (in a good way).

  11. AdvancedComing soon

    System Design Fundamentals

    Scaling, load balancing, caching, replication, and queues — put every step of this track together by designing real systems like a URL shortener or a payment service.

AI

6 of 6 ready

Build real features on top of large language models — chatbots, RAG, and agents.

  1. Beginner

    How LLMs Work (for Developers)

    Tokens, probabilities, temperature, training, embeddings, context windows, prompts, and hallucinations — how large language models really work, learned by building a tiny one yourself.

    Start tutorial· 10 Chapters

  2. Beginner

    Build a Chatbot with an LLM API

    Call a language model over HTTP, keep conversation memory, stream the reply, protect your API key behind a backend, handle errors and cost, and ship a web chat UI — built step by step with Node.js.

    Start tutorial· 8 Chapters

  3. Intermediate

    Math for AI

    Vectors, dot products, matrices, derivatives, gradient descent, probability, and a tiny neural network that learns — the intuition behind embeddings and training, learned by building a small toolkit instead of reading proofs.

    Start tutorial· 8 Chapters

  4. Intermediate

    RAG: Chat with Your Own Documents

    Make a language model answer from your own files: split documents into chunks, turn them into embeddings, search by meaning, build a grounded prompt with citations, improve retrieval, and measure whether it works.

    Start tutorial· 8 Chapters

  5. Intermediate

    AI Agents with Tools & MCP

    Let a language model call your functions to get real work done: tool calling, the agent loop, well-designed tools, memory and planning, the Model Context Protocol (MCP), and the safety rules that keep an agent from doing harm.

    Start tutorial· 11 Chapters

  6. Intermediate

    Docker Sandboxes Crash Course

    Isolated dev environments in 1 hour, then a deeper dive into AI agent sandboxing — kits, environment files, the MCP gateway, and multi-agent workflows.

    Start tutorial· 13 Chapters

Cybersecurity

1 of 5 ready

Learn how apps get attacked, and how to build and run them so they don't.

  1. BeginnerComing soon

    Security Fundamentals for Developers

    Hashing vs encryption, HTTPS, secrets management, and the mindset of thinking like an attacker.

  2. IntermediateComing soon

    OWASP Top 10 by Example

    Break a deliberately vulnerable app in a safe lab — SQL injection, XSS, broken auth — then fix each hole.

  3. Intermediate

    Keycloak Crash Course

    OAuth 2.0, OpenID Connect, and JWTs in about an hour — run Keycloak locally, build a realm and client by hand, decode a real access token, and protect a NestJS API with it.

    Start tutorial· 8 Chapters

  4. IntermediateComing soon

    Hardening a Linux Server

    SSH keys, firewalls, updates, and least privilege for the server your app runs on.

  5. AdvancedComing soon

    Intro to Penetration Testing

    Recon, scanning, and reporting — practised only on your own lab machines, the ethical way.

Mobile Apps

0 of 4 ready

Build apps for Android and iOS and get them into people's hands.

  1. BeginnerComing soon

    Mobile Development Fundamentals

    Native vs cross-platform, how mobile apps are built and shipped, and choosing where to start.

  2. BeginnerComing soon

    Your First Mobile App

    Screens, navigation, and state — build a small app and run it on your own phone.

  3. IntermediateComing soon

    Connect Your App to a REST API

    Fetch and send data, handle loading and errors, and log users in — pairs with the NestJS Crash Course.

  4. AdvancedComing soon

    Publish to Google Play & the App Store

    Signing, store listings, review rules, and shipping updates to real users.

Desktop Apps

0 of 4 ready

Build installable apps for Windows, macOS, and Linux.

  1. BeginnerComing soon

    Desktop App Fundamentals

    How desktop apps differ from websites, and the main ways to build one today.

  2. BeginnerComing soon

    Your First Desktop App

    Windows, menus, and talking to the operating system — build a small tool you'd actually use.

  3. IntermediateComing soon

    Files, Local Storage & Offline Data

    Read and write files safely, store data locally, and keep working without the internet.

  4. AdvancedComing soon

    Package, Sign & Auto-Update

    Turn your app into an installer for Windows, macOS, and Linux, and ship updates automatically.

Career & Teamwork

0 of 4 ready

The skills no framework teaches — working in a team, getting hired, and growing as an engineer.

  1. BeginnerComing soon

    How Software Teams Work

    Agile and Scrum in practice — sprints, standups, tickets, and breaking a feature into tasks you can actually estimate.

  2. BeginnerComing soon

    Pull Requests & Code Review

    Write PRs that are easy to review, give feedback that helps instead of hurts, and learn from every review you get.

  3. BeginnerComing soon

    Landing Your First Developer Job

    A CV that gets read, a portfolio that shows real work, and how to prepare for technical interviews in Cambodia and beyond.

  4. IntermediateComing soon

    Growing from Junior to Mid-Level

    Own features end to end, estimate honestly, communicate early, and start helping the people who join after you.