We have entered an era where it has become incredibly easy for web developers (especially React developers) to launch apps. With Expo, you can release both Android and iOS apps even faster. Let's become developers who can quickly launch apps through Expo.

Learn React through web games. Get familiar with Classes and Hooks, and learn additional things like Context API, React Router, Webpack, and Babel.

Learn NestJS, often called the Spring of Node.js, and experience the convenience of Dependency Injection. Learn everything from API development and comparisons with Express to deployment and testing.

You will learn about what a node is, the latest JavaScript grammar, the node API, npm, the module system, databases, testing, and more. You will create a project using five practical examples. You will also deploy a service to the cloud and convert a node project to TypeScript.

With the arrival of the AI era, the skills required of developers are becoming increasingly complex. You might have thought, "I just need to be good at frontend," but when you try to create your own service or integrate AI features, you eventually hit a massive wall called the backend. However, as you try to start backend development, are you overwhelmed by how much there is to learn—from database design and authentication (Auth) to storage management and complex infrastructure setup? Now, you can lay down that heavy burden. In this course, we use Supabase, which solves all these backend functions at once. We will guide you through the fastest shortcut to becoming a full-stack developer who can "instantly" complete a backend without complex server knowledge and bring ideas to life immediately.

In this course, we will practice developing programming thinking skills using JavaScript. Starting with a multiplication table web game, we will build various projects together, including Word Chain, Number Baseball, Response Rate Test, Tic-Tac-Toe, Lotto Generator, Rock-Paper-Scissors, Card Matching Game, Text RPG, Minesweeper, 2048, and Whack-a-Mole.

Learn about the uses, pros and cons of various design patterns while creating a drawing board with TypeScript/JavaScript. Learning the canvas API is a bonus!

In this lecture, we will show you when testing is necessary and the advantages of testing using the Jest framework. We will apply unit testing and integration testing to React, Express, etc.

We will create an SNS service similar to Twitter (X.com) using the React19 & Next15 & ReactQuery5 & Next Auth5 & MSW2 & socket.io4 & zustand stack. Finally, we will add SSR for search engine optimization!

Data structures are essential subjects for studying algorithms! Let's learn various data structures using JavaScript!

If you are already a developer or want to become a developer but did not major in computer science and are weak in databases, gain lifelong knowledge with this one course!

If you are a developer who deals with HTTP or want to become a developer but did not major in computer science and are weak in networking, gain lifelong knowledge with this one course!

Now that you have learned the basic syntax of TypeScript, let's explore how to analyze the complex types found in famous libraries.

Learn the basic syntax of TypeScript, and explore how to analyze types written by others as well as how to write your own types.

We are building a delivery app for riders using React Native. This is a lecture by a developer who has built more than 5 apps with React Native over 6 years and successfully sold their company to Kakao Mobility.

Let's start full-scale React web development by building a Slack clone! From sign-up and login to creating rooms and real-time chat!

We will create a Twitter-like SNS service using the React & Next & Redux & Redux-Saga & Express stack. Finally, we will perform search engine optimization and deploy it to AWS.

Let's apply TypeScript to Node.js, add typings to existing npm packages, or create your own TypeScript library.

Let's use React and TypeScript together by adding TypeScript to a web game made with React and React Router, Redux, and MobX.

Are you having trouble deciding between Redux and MobX? Let's learn both first and then decide!

Systematically learn the distributed NoSQL database Cassandra, from basic concepts to practical application. Develop high-volume data processing capabilities through practice-oriented theory and hands-on exercises, including data modeling, query optimization, and cluster configuration. Even without prior database experience, you can grow into a Cassandra expert based on the know-how of a current Silicon Valley developer.

JavaScript, TypeScript Next is backend development! You will be able to develop REST API backends using NestJS, develop and deploy Socket IO.

We will delve deep into the 'Stream Architecture,' which controls massive 10GB datasets with just 50MB of memory, to grasp the essence of physical resource management. Based on this, you will design data pipelines that directly control the Operating System (OS) and the V8 engine, evolving into a top 1% high-end engineer that AI can never replace.

If you feel lost about what to learn in an era where AI writes code, you can find clear answers in the principles of UNIX and the kernel—the unchanging essence of systems. Through a practical project that integrates Node.js with a C language engine (FFmpeg), this course delivers the perspective of the top 1% of architects who command entire systems without being swayed by technology trends.

If you don’t know why things keep breaking when you have AI do it, the problem isn’t coding—it’s telling it what to do without understanding “what’s happening.” I’ll teach you vibe coding by taking a web service with login and payments from scratch all the way to launching it on your own domain and getting it indexed by search engines, while understanding the context behind “What just happened?” at every step.

Drawing from my own experience of feeling despondent when trying to implement practical code during my first MSA transition—despite knowing the theory—I will help you grow into a developer who guarantees perfect data consistency amidst any system failure by directly rolling back daunting compensation logic through 9-step practical patterns and AI Agent coding.

Learn the latest Next.js with the official documentation. Understand why Next.js is needed as a problem-solving tool!

After completing all lectures, you will be able to develop a web service yourself.

In an era where AI writes code for us, the value of a "true architect" who can see through and control the macroscopic framework of a system becomes overwhelmingly higher. This course digs into the essence of low-level networks and TCP/UDP sockets hidden behind frameworks, cultivating the ability to design robust core engines that never crash even in the face of millions of traffic hits and large-scale data. Go beyond being a coder who blindly repeats copy-pasting, and leap forward to become an irreplaceable master who directs and controls AI with clear, system-level solutions.

Learn about the uses, pros and cons of various design patterns while creating a drawing board with TypeScript/JavaScript. Learning the canvas API is a bonus!

This course aims to help even those new to Astro complete a live, deployed blog within one hour. We minimize theoretical explanations and focus on copy-and-paste ready code and step-by-step checkpoints. By the end of the course, 👉 You won't just be someone who "has tried Astro," 👉 You will be someone who "has a blog built with Astro."

Stop asking developers every time! Create websites and various services without using expensive outsourcing!

While LLMs are currently transforming the development environment, what truly matters is not just "writing code on your behalf" but integrating them as features into a service. This course provides a step-by-step guide to implementing a lightweight yet polished Tarot reading service using Next.js and the OpenAI API. In the first stage, we will build an MVP that works without a backend, connecting the user input flow (questions/threads/card selection) to result generation. In subsequent stages, we will expand the functionality by building a backend, implementing general login and OAuth, adding community features, and creating a reading dashboard. Finally, we will conclude by deploying to AWS and integrating Google AdSense to complete a service ready for actual operation. Additionally, we will cover understanding pricing structures and cost optimization strategies to ensure that LLM API usage costs do not become a burden.

This course is a practical, hands-on guide for those who want to learn how to maximize development productivity in the AI era. Beyond simply learning how to use AI, we focus on how to utilize Claude Code in a real-world development environment and how to produce "proper results." Many developers use AI but still face issues such as: ❌ Inconsistent results ❌ Poor code quality ❌ Increasing project complexity To solve these problems, this course teaches you how to utilize AI as a "development partner" rather than just a tool through: ✔ Spec-based workflows ✔ Structured command systems ✔ Sub-agent and automation strategies Furthermore, you will gain the experience of completing and deploying a full application from start to finish by integrating with real-world services such as Firebase, Figma, GitHub, and Vercel.

Now that you have learned the basic syntax of TypeScript, let's explore how to analyze the complex types found in famous libraries.

This course goes beyond basic CRUD-level database usage, helping you develop the PostgreSQL skills needed in the AI era from a practical, real-world perspective. Drawing on AI development experience in Silicon Valley, you’ll gradually learn how to design and use JSON, indexes, transactions, and pgvector in actual services, while gaining the skills to solve complex data structure and performance problems.

We will apply it in practice by crawling sites such as Naver, Amazon, Twitter, YouTube, Facebook, Instagram, and unsplash.com.

This course is designed to help even those new to MySQL understand it easily, starting from the basic concepts of DBMS and progressing step-by-step to the ability to write SQL that can be applied in real-world practice. To solve the problems learners frequently encounter (e.g., SQL syntax is difficult, not knowing how to write queries, or not understanding the flow of data processing), the course is structured with repetitive theory and practice, helping you naturally build your skills through a hands-on approach. In particular, the focus is not on simple memorization of syntax, but on understanding "why it is written this way" through the process of handling actual data.

This is a TypeScript course designed to help you become a top-tier web developer through in-depth lessons. By completing this course, you will gain a profound understanding of the essence of TypeScript, enabling you to master React, Next.js, NestJS, and more.

At some point in backend development, you start to have these concerns. It's that moment when services expand and traffic increases, and you begin to feel the limitations of simple REST communication and CRUD structures. I experienced these same issues in the field and went through much trial and error balancing performance and structural complexity. The solution I chose during that process was NATS. Its simple configuration based on a single binary, ultra-low latency performance in microseconds, and the fact that it provides essential features—from Pub/Sub to Queue Groups and JetStream—without being overkill made it a very practical choice for real-world service environments. This course is not just a list of NATS features. Based on the problems I faced in practice, I explain through code and workflows why I chose NATS in certain situations and how I designed the architecture. This course is designed to help everyone—from those new to messaging systems to backend developers preparing for employment and senior developers considering better architectures—understand distributed systems and grow to the next level.