Everything About Structure Navigation and Manipulation - [Complete DOM Mastery Part 1]

Have you ever thought about building a 'real system' beyond simply rendering screens? The real problem many developers commonly face is something else entirely. It's the limitation of a 'fake full-stack'—where things look plausible on the surface, but data synchronization frequently tangles, speed is frustrating, and you lose track of where to even start when just a few features are added. This isn't a problem that can be solved by simply memorizing one more Next.js feature. This course will resolve that frustration from the roots. Encyclopedia-style classes that just list features are boring, aren't they? Instead, we have tightly integrated the fundamental principles of Computer Science (CS) with the advanced architecture of Next.js. We will directly transplant into your fingertips the enterprise-level design skills required to flexibly withstand millions of visitors and maintain perfect data consistency.

We solve the fundamental problem of losing control amidst AI-generated fragmented code and the complex React ecosystem by opening the hood and engineeringly analyzing the internal workings of core React libraries such as Zustand, TanStack Query, React Hook Form, Zod, and the React Compiler. By moving beyond simple tool usage and mastering how to directly manipulate the performance and data flow of the React engine, you will build the solid 'enterprise architecture design muscle' necessary to respond immediately to any crisis.

Next.js 15's App Router is a powerful architecture for building high-performance web services by providing complete control over the boundaries between server and client. This course clearly connects complex rendering mechanisms—from the operational principles of React Server Components (RSC) to the three major caching strategies (Static, Dynamic, and ISR)—through 12 practical missions. Through this, you will gain the ability to design file-system routing and nested layouts to meet business requirements, completely breaking free from the anxiety of "vibe coding" where you copy code without understanding the underlying principles. Ultimately, you will transform into a Next.js architect who can instantly spot the blind spots in AI-generated code and proactively direct the optimal structure.

This is not just a lecture you listen to and forget. This course aims not for "the moment you understand React," but for "the moment you can actually work with React." In every section, you'll complete missions alongside the lectures, solve practice problems yourself, and learn by implementing core concepts like JSX, Virtual DOM, State, and useEffect with your own hands. When you finish the course, you won't just be a beginner who knows React syntax—you'll be a developer who can explain and utilize everything from component design to rendering flow on your own. "Not a class you just listen to, but learning you build through completion." Understand the essence of React and experience the world of declarative UI firsthand.

The real world is unforgiving. I will thoroughly pass on my optimization expertise through a meticulous mission system, showing you how to design smooth user experiences even in extreme environments where tens of thousands of real-time data points pour in. Go beyond simply writing code and leap forward to become an irreplaceable senior engineer who dissects performance through understanding engine principles.

This course covers the entire Critical Rendering Path (CRP) process, from the moment the browser receives HTML to create the DOM, to combining it with the CSSOM and painting pixels on the screen. Moving beyond simple DOM manipulation, you will learn how CSS and JS impact performance, as well as practical strategies to noticeably improve real-world web performance—including image and font optimization, Lazy Loading, Intersection Observer, virtual lists, and hands-on practice with DevTools.

This course goes beyond simple DOM manipulation, deeply learning how to dynamically compose and react to web UIs within interactions with actual users. It's structured for you to learn by directly implementing common issues encountered in practice, from the essence of event systems, bubbling and capturing, event delegation, real-time UX feedback, to performance optimization using throttle & debounce. Based on an understanding of the DOM tree structure, you will develop the ability to flexibly connect event flow and state changes.

The "Learning HTML + CSS Properly: Complete Mastery from Beginner to Practical Application Part 1" course is designed to provide a deep understanding of how the internet and the web work, and to solidify the basics of HTML/CSS through a practice-oriented curriculum. By taking this course, you can firmly grasp the essential concepts of web development and immediately apply them to projects.

An Express.js journey from beginner to mastery, flowing like water! A backend journey where you learn properly by directly implementing from basic server concepts to completing a CRUD project.

This course goes beyond just using Express.js—you'll implement its internal engine from scratch to truly understand how real servers work. You'll gain hands-on experience growing as a server developer by building all of Express's components from the ground up, including routers, middleware, request-response objects, static file handling, and template rendering.

This course is a full-stack level frontend project course that focuses on implementing Notion from start to finish using Vanilla JavaScript, going beyond simple UI cloning to deeply understand the internal operating principles. You'll implement all the core features of a real note-taking app using vanilla JS, including sidebar tree, nested document creation, auto-save, routing, trash, favorites, search modal, settings modal, theme switching, Export/Import, keyboard shortcuts, responsive layout, drag resize, and more. The goal is to solidly learn browser standard behaviors (event bubbling, DOM tree, local storage, Blob, FileReader, hash routing, etc.) that you must know before frameworks like React and Vue, so you can completely understand "why it works this way" and build the skills to debug effectively.

This course goes beyond simply using Express.js. You will rebuild its internal engine from start to finish, gaining hands-on experience with the real principles of how a server works. By directly creating each component of Express—such as routing, middleware, request–response objects, static file handling, and template rendering—you will grow as a server developer and truly understand how a framework operates at its core.

📌 This course is a curriculum that starts with a strategic AI tic-tac-toe project and completes core object-oriented programming concepts through practical examples. You'll train logic design and AI strategic thinking through game implementation, then directly experience OOP design techniques like inheritance, composition, delegation, and encapsulation through code. This is recommended for those who want to grow beyond syntax into a 'developer who designs' through real projects.

Through this course, students will broadly learn the basics and advanced concepts of JavaScript, from setting up the development environment to variables, conditional statements, functions, objects, and arrays. Through thorough review with practice exercises and quizzes, they will be able to develop problem-solving skills that can be immediately applied to web and mobile development practices.

This course systematically masters intermediate to advanced CSS techniques such as "CSS Position, Transition, Transform, Animation, Flexbox, Grid, and Responsive Web Design," and equips you with skills immediately applicable in real-world projects through various hands-on practice projects.

This course covers the entire Critical Rendering Path (CRP) process, from the moment the browser receives HTML to create the DOM, to combining it with the CSSOM and painting pixels on the screen. Moving beyond simple DOM manipulation, you will learn how CSS and JS impact performance, as well as practical strategies to noticeably improve real-world web performance—including image and font optimization, Lazy Loading, Intersection Observer, virtual lists, and hands-on practice with DevTools.

DOM is the essential foundation of dynamic applications. This course covers everything from the basics to the advanced application of all events occurring in and triggered by Element, Document, and Window objects. You will thoroughly learn and be able to utilize Web Components (Custom Element, Shadow DOM, Template). Together with the "DOM Mastery: Basics" course, you can bring your DOM expertise to completion.

This course goes beyond simple DOM manipulation, deeply learning how to dynamically compose and react to web UIs within interactions with actual users. It's structured for you to learn by directly implementing common issues encountered in practice, from the essence of event systems, bubbling and capturing, event delegation, real-time UX feedback, to performance optimization using throttle & debounce. Based on an understanding of the DOM tree structure, you will develop the ability to flexibly connect event flow and state changes.

Throw away those simple services you can make with vibe coding in just 10 minutes! You can learn 'real' practical vibe coding. Let's create advanced services at the level of actual services according to planning and design with Cursor AI NCOP. No Code, Only Prompt

This is a full-stack series course aimed at developing web and app services at a commercially viable level for beginners, based on real-world experience developing web services in the field. As Part 2 of this series, this course thoroughly covers the latest HTML5, CSS3, and vanilla JavaScript + ES6, considering responsiveness and compatibility among the various frontend technologies available.

Now you can truly start to 'see' React. Learn advanced concepts and Hooks in the easiest and most accurate way.

You cannot talk about web programming without knowing the DOM. This covers over 95% of the DOM specification. It is the definitive guide to the DOM—broad, deep, and detailed. You won't waste time, money, or effort. It also covers JavaScript practical application, enabling you to develop web applications with Vanilla JS.

In this course, you will be able to create a Reddit website from scratch, step by step.

This course is designed to learn the JavaScript programming language along with the latest ES6 grammar.

It covers machine learning concepts within the JavaScript environment. It covers the patterns and code for implementing machine learning with JavaScript and TensorFlow.js.

You can learn JavaScript from basic to intermediate, which is the foundation of web development.

This course goes beyond just using Express.js—you'll implement its internal engine from scratch to truly understand how real servers work. You'll gain hands-on experience growing as a server developer by building all of Express's components from the ground up, including routers, middleware, request-response objects, static file handling, and template rendering.

A practical production class on creating responsive web pages that can implement various layouts for each device using only pure HTML/CSS/JS without using Bootstrap [2024 Latest Edition].

"A hands-on web development project course that covers everything from planning and design to implementation and deployment using Generative AI." We will complete the entire process together step-by-step—starting from idea conception, quickly creating designs with AI, implementing a functional website with React, and finally deploying it to the internet. Latest AI tools like Stitch and Figma Make will assist with your design work, and even complex coding will be taught in a way that is easy to follow step-by-step.

Through this lecture, students can create a web service similar to Instagram using HTML, CSS, and JS. (Only the front-end is implemented! The back-end server construction will be filmed in a later lecture.)

In the era of swift execution and validation, execute faster than anyone with VIBE Coding! Achieve complete monetization, from ads to payments, all by yourself.

For over 15 years, Young Codi Kim, a star coding instructor, has been dedicated to coding education for elementary school students, high school students in IT software departments, university students in computer science, and job seekers without a major in the field. Now, you can experience Kim's easy and fun coding lectures not only offline but also online. With Young Codi Kim, who has trained over 500 front-end, back-end, full-stack, and web developers, your dream of becoming a developer will soon become a reality!

In this course, you will learn how to create a chatbot using the API provided by Google.

Based on the experience of wondering how facial recognition works in offline environments on-site, this course will guide you through building the basic structure of a facial recognition-based access and attendance management system using React + Electron and Python's FastAPI-based DeepFace. Rather than focusing on perfection, we focus on understanding the operating principles and laying the foundation for you to expand into your own personal projects.

Data can be processed and presented in tabular form, but the most important thing is to present the data in a way that humans can understand at a glance.