If you’ve been building React apps but feeling like you’re missing a layer of safety and clarity, this is the course for you. You will learn how to refactor a real-world project to be fully type-safe, more readable, and significantly easier to maintain.

In this tutorial, Rachel Johnson walks you through the entire process, including:

• Refresher on Vanilla TypeScript: A quick warm-up to get you back in the mindset.

• Typing useState: Moving from inferred types to explicit, foolproof state management.

• Component Architecture: How to define custom prop types, handle functional component returns, and keep your code modular.

• Function Props: Mastering the common pattern of passing callbacks between components with confidence.

By the end, you’ll have a foundational understanding of how TypeScript fits into a modern React workflow, helping you catch bugs before they even reach your browser.

Watch the full course on the freeCodeCamp.org YouTube channel (1-hour watch).

In our latest video, we cover the recurring, massive outages of AWS’s US-East-1 region.

When the internet goes down, it often feels like a mysterious, singular event. But the history of US-East-1 is a story of compounding complexity. From a network upgrade gone wrong in 2011 to a single missing DNS record in 2025, we trace how one specific data center cluster in Northern Virginia became the unintentional "connective tissue" of the modern web

This is a story about how systems this large don't fail in the ways we predict, they fail in the ways we forget to protect against.

Watch the full video on the freeCodeCamp.org YouTube channel (16-minute watch).

We hope you enjoy this deeper dive. Let us know what you think of this video essay format and what topics you'd like us to explore next.

Led by Mumshad Mannambeth, founder of CodeCloud, this full-length course is designed to take you from the absolute fundamentals of Large Language Models (LLMs) to building specialized, multi-agent systems.

Here are the core things you will learn in this course:

• LLM Core Concepts: Learn how generative pre-trained transformers (GPT) work, understand tokens and tokenization, and see how temperature shapes model predictability.

• Workflows vs. Agents: Learn the important architectural distinction between predefined code pathways (workflows) and fully autonomous loops where the AI decides its own next steps using tools.

• Hands-on Implementation: Build four distinct agent personalities from scratch: Zippy (the orchestrator), Savvy (the research specialist utilizing the React pattern), Meshi (the memory manager), and Cody (the code and automation specialist).

• Production Patterns & Security: Explore critical design patterns including structured JSON outputs, input/output guardrails, human-in-the-loop approvals, and secure sandbox execution.

• OpenClaw Case Study: Wrap up the course by dissecting OpenClaw, a popular open-source, production-grade personal assistant framework. You will trace its 5-phase loop, check how it manages session state, and see how it dynamically builds a 19-section system prompt based on real-world research.

Watch the full course on the freeCodeCamp.org YouTube channel (3-hour watch).

This course covers the full spectrum of time handling in modern web development:

• Core Concepts: Understand epoch time, time zones, and the real reasons why time is relative.

• JavaScript Date Object: Learn how the native Date object works, its common pitfalls, and how to avoid bugs related to mutation and zero-indexed months.

• The Power of INTL: Master the underrated Internationalization (INTL) API to format dates, times, and relative time (e.g., "3 days ago") without relying on heavy third-party libraries.

• The Future with Temporal: Get an introduction to the new Temporal API—the modern, immutable replacement for the legacy Date object that finally brings proper time zone and DST support to JavaScript.

• Proactive Strategies: Learn how to avoid silent production bugs caused by daylight saving time (DST) and incorrect time zone handling.

By breaking the topic down into logical parts, this course ensures you understand why time related issues happen, not just how to patch them.

You can watch the full course on the freeCodeCamp.org YouTube channel (2-hour watch).

To help you learn this important tool, we just released a complete Command Line Basics for Beginners course on the freeCodeCamp.org YouTube channel.

Learning the CLI allows you to:

• Boost Your Efficiency: Perform complex file operations in seconds.

• Unlock Advanced Tools: Many essential developer tools, cloud platforms, and data analysis packages only run via the command line.

• Prepare for the Industry: Whether you want to go into software development, DevOps, or data science, command line proficiency is a non-negotiable skill.

By the end of this course, you will know how to set up and use the terminal locally on your own computer.

Here are some of the core commands and concepts you'll master:

• Navigating the File Tree

• Managing Files

• Handling Directories

• Reading and Writing Data

Watch the full course on the freeCodeCamp.org YouTube channel (1-hour watch).

We just posted a new course on the freeCodeCamp.org YouTube channel, where instructor Kian Kyars provides a hands-on guide to mastering Distributed Data Parallelism (DDP).

The course shows you how to overcome memory limitations by training models effectively across multiple GPUs. You will explore the theory behind distributed training, including the critical differences between data parallelism and model parallelism, before diving into the DDP workflow. Through a series of practical steps, you will learn to implement manual batch averaging, work with an "All Reduce" sandbox, and utilize DDP hooks to optimize your training processes.

By the end, you will have a deep understanding of the performance trade-offs involved in distributed systems and the expertise to implement them in your own AI projects.

Watch the full course on the freeCodeCamp.org YouTube channel (2-hour watch).

In our latest freeCodeCamp.org video, "Why Computers Can’t Count Money," Ania Kubow dives into the history of a class of software bugs that once challenged major financial institutions, leading to accounts that gained or lost funds due to microscopic rounding errors.

The issue stems from how hardware processes information: because computers store numbers in binary (base-2) rather than the base-10 system humans use, they struggle to represent simple decimals like 0.1 or 0.2 exactly. Instead, machines store the closest possible approximation of these numbers. While this seems trivial for most applications, these tiny discrepancies accumulate when scaled across millions of transactions, causing financial balances to "drift" in ways that could occasionally be exploited to generate money from nothing.

This technical quirk forced the entire financial industry to rethink how they handle currency in software. Today, modern financial systems avoid floating-point numbers entirely, choosing to store values as integers to ensure absolute precision. This video explores the engineering shift required to guarantee that 0.1 plus 0.2 always equals 0.3, protecting the integrity of every payment you make online.

Watch the video on the freeCodeCamp.org YouTube channel (6-minute watch).

In this project-based course, instructor Shawn Esquivel takes you through the entire development lifecycle, showing you how to move beyond simple chat interfaces to create an intelligent system capable of managing workflows across your favorite apps.

You will start by building the agent's body using the Vercel AI SDK to create a responsive, chat-based interface that supports dynamic content like code blocks and weather forecasts. Once the foundation is set, you will develop the agent's brain by connecting to the latest high-performance AI models via the Vercel AI Gateway, enabling it to reason, plan, and execute complex tasks.

You will build a chat-based "body" with the Vercel AI SDK and connect high-performance AI "brains" via the Vercel AI Gateway. Using Composio, you will add "hands" to autonomously manage cross-app workflows across platforms like Gmail and Slack. The course further enhances this system by integrating SuperMemory for long-term recall and Telegram for mobile access. Finally, you will implement Vercel Cron jobs to give your agent a "heartbeat," enabling it to run scheduled tasks independently.

The course utilizes Cursor, an agentic AI code editor, to help streamline development, troubleshoot bugs, and generate code throughout the process.

Watch the full course on the freeCodeCamp.org YouTube channel (1-hour watch).

We just released a comprehensive, free course on the freeCodeCamp.org YouTube channel that will teach you everything you need to know about Notion Workers. Developed by Notion expert Matthias Frank, this course breaks down everything from initial setup to launching your very first automated worker.

Notion Workers represent one of the biggest updates Notion has ever shipped. Historically, if you wanted to build advanced automations, you had to rely on external no-code tools to patch the gaps. Workers change this by letting you build powerful, native automations directly.

And here is the best part: you do not need to know how to code. While they sound highly technical, the rise of AI means that artificial intelligence can do the heavy lifting on the backend. You genuinely don't need a computer science degree or an engineering background to deploy these.

Watch the full course on the freeCodeCamp.org YouTube channel (1-hour watch).

In this hands-on project, you will learn to bridge the gap between DevOps and automation by integrating GitHub, OpenAI, and n8n to create a workflow that works for you even when you're offline. Farzeen guides you through every step of the implementation: from setting up your development environment and building a robust Node.js/Express application, to implementing a sophisticated AI-driven log analysis system that automatically detects failures, generates patches, and opens pull requests on your behalf.

The course goes beyond the basics by showing you how to secure your automation using GitHub Secrets, configure N8N webhooks, and ensure your system is production-ready. You will also learn how to set up automated email notifications, keeping your entire team in the loop without you ever having to lift a finger.

By the end of this tutorial, you will have the knowledge to reduce downtime and spend more time building great features. Watch the full course on the freeCodeCamp.org YouTube channel (1-hour watch).

We just published a new tutorial on the freeCodeCamp.org YouTube channel, featuring software developer and course creator Ania Kubow.

In this comprehensive, beginner-friendly course, Ania teaches you a much simpler, more efficient approach. Instead of building scrapers from scratch, you will learn how to leverage an API to handle the heavy lifting for you.

Throughout this tutorial, you will master the following:

• How to bypass web scraping obstacles like bot protection and rate limits using SerpApi, the Web Search API.

• How to extract structured JSON data directly from search engines like Google, Amazon, YouTube, and more.

• How to use the Google Lens API to scrape images and visual matches.

• How to build your own functional web application that searches for and downloads content locally to your computer.

By the end of this video, you will have the knowledge and the basic code necessary to turn internet data into actionable insights for your own projects.

Watch the full tutorial on the freeCodeCamp.org YouTube channel (1 -hour watch).

The ability to scale applications instantly and ship software reliably is an important skill. Containerization is at the heart of modern development.

This hands-on, structured course is designed to take you from absolute scratch to becoming job-ready. Taught by instructor Eissa from DolfinEd, who brings over 25 years of industry experience and 21 years of teaching expertise, this course breaks down complex concepts into simple, actionable skills.

This is a complete, step-by-step practical course that covers everything you need to master Docker:

• Foundations: Understand the shift from legacy physical servers to virtual machines and containers.

• Core Skills: Master Docker files, image creation, and how to manage repositories using Docker Hub.

• Networking & Storage: Learn the gold standards for managing container networking, storage, and volumes.

• Orchestration: Move beyond basic containers by learning how to deploy multi-container applications with Docker Compose and get an introduction to Docker Swarm.

• Real-World Application: Put your skills to the test with structured quizzes, module assignments, and real-world projects that mirror professional environments.

Watch the full course now and start your journey to becoming a Docker expert (7-hour watch):

In this hands-on project, you will learn to create a production-ready AI-powered Slackbot capable of handling complex research and data analysis. The bot automatically detects when new members join your Slack community, researches their professional background via email and GitHub, and utilizes OpenAI's GPT-4 to score their fit for your business.

This course takes you from zero to deployment, covering essential modern development tools and practices:

• Backend Development: Using Node.js, Express, and Slack Bolt.

• AI Integration: Connecting to OpenAI’s GPT-4 to perform intelligent lead qualification.

• Database Management: Implementing a PostgreSQL database on Render to store member information and fit scores.

• Infrastructure as Code: Using Render blueprints to define, deploy, and manage your project infrastructure.

You can watch the full course now on the freeCodeCamp.org YouTube channel (2-hour watch).

To get the data you need today, you have to bypass sophisticated anti-bot detection systems.

We are just posted full-stack web scraping course on the freeCodeCamp.org YouTube channel. Gavin Lon developed this course.

Many scraping tutorials focus on basic scripts that fail the moment they hit a real-world website. This course bridges the gap between a "toy script" and a production-ready application. You'll learn how to bypass advanced fingerprinting and bot detection using managed browser infrastructure and residential proxies.

Gavin will teach you how to build a fully deployed MERN (MongoDB, Express, React, Node.js) application. It's a dashboard that visualizes live data scraped from major platforms like Amazon, Booking.com, Indeed, and the TIOBE Index.

Evomi provided a grant to make this course possible. You can try out Evomi here: https://evomi.com/freecodecamp

Here are the key things you will learn in the course:

• Master Modern Scraping: Move beyond basic libraries to use Playwright, Cheerio, and Evomi’s enterprise-grade Scraping Browser and Scraper API.

• Defeat Anti-Bot Systems: Learn exactly why standard scripts get flagged and how to configure residential proxies and browser fingerprints to remain undetected.

• Full-Stack Integration: Learn how to pipeline raw data into a MongoDB database and build a clean, responsive UI with React, Vite, and Bootstrap.

Watch the full course on the freeCodeCamp.org YouTube channel (6-hour watch).

We just published a comprehensive six-hour course on the freeCodeCamp.org YouTube channel that takes you from Figma basics to professional-grade, high-fidelity prototyping. Through hands-on, real-world projects like travel and food delivery apps, you’ll gain practical experience with advanced components, Auto Layout, and 3D elements to build a production-ready design portfolio. Wish Naik developed this course.

You’ll learn core Figma tools and advanced UI/UX concepts, including:

• Figma interface, tools, and essential shortcuts

• Professional style guides and color systems

• Low-fidelity wireframes to high-fidelity prototypes

• Components, Auto Layout, and Constraints

• Real-world projects like travel websites, car dealership sites, and food delivery apps

• Advanced techniques such as multi-dimensional components and 3D web elements

Watch the full course on the freeCodeCamp.org YouTube channel (6-hour watch).