Becoming a Java Backend Developer! Introduction to Spring Boot 3 Framework based on Java 17 (2)

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.

This course is designed for developers, AI enthusiasts, and professionals who want to develop real-world AI applications using LangChain, OpenAI, Hugging Face, and Python. Rather than focusing solely on theory, this course takes a practical, project-oriented approach. Throughout the course, students will directly build a total of 15 high-quality AI applications, including chatbots, CSV analysis tools, resume screening systems, invoice extraction bots, support assistants, marketing tools, and text-to-SQL applications. I created this course to make complex AI concepts easy to understand and to ensure modern LLM development is accessible to everyone. Many learners struggle to understand how tools like LangChain, embeddings, memory systems, vector databases, and AI agents interact in real-world applications. This course guides you step-by-step through clear explanations, hands-on coding sessions, and actual implementation workflows. By the end of the course, students will confidently understand how to design, build, and deploy AI-powered applications using the latest generative AI technologies.

This course goes beyond simple grammar explanations and focuses on developing C++ programming skills that can be applied immediately in the field. Throughout my teaching, I have directly addressed common challenges faced by many learners—such as struggling to understand the STL or feeling confused by file handling and exception handling concepts. Based on this experience, I provide step-by-step explanations to ensure even complex concepts are understood easily and clearly. Furthermore, this course is not just about delivering theory; it is structured around: 👉 "Why this concept is necessary" 👉 "How it is used in actual code" 👉 "How it is applied in professional practice"

This is an introductory course designed for those learning Rust for the first time, structured to help you learn step-by-step from the basics. Many learners encountering Rust for the first time often find it difficult due to: - Unfamiliar syntax - The burden of memory concepts - Differences from existing languages (C/C++) To solve these problems, this course helps anyone understand Rust naturally through: 👉 Easy explanations 👉 Step-by-step curriculum 👉 Repetitive practical examples Rust is a modern systems programming language that offers both safety and performance, making it a very important technology in the future development landscape. Build a solid foundation of Rust's core basics through this course.

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 course explains everything from the basics of MySQL to its practical application in a step-by-step manner, making it easy to understand even for those learning databases for the first time. Rather than just providing simple theoretical explanations, the course focuses on real-world problem scenarios and teaches you how to write SQL and handle data through hands-on practice. The curriculum is systematically structured to cover the entire process, from DBMS concepts to MySQL installation, basic SQL syntax, data manipulation, and the use of functions. In particular, the goal is to help you understand "why it is written this way" through repetitive practice and to develop the ability to write queries on your own.

This course is a practical, hands-on guide to automating repetitive tasks and maximizing work productivity using ChatGPT and Python. You will learn step-by-step how to use AI to automate daily repetitive tasks such as Excel work, report writing, sending emails, and data organization. Starting as a non-developer myself, I have taught AI automation to thousands of students, and I have compiled only the methods that can be used immediately in actual business environments. This course focuses not on complex theories, but on **"automation techniques you can use right today."** 👉 The goal is to turn ChatGPT into more than just a tool, but into **your own personal work assistant (Jarvis)**.

This course is an introductory lecture for those learning the Java 17-based Spring Boot 3 framework for the first time. It is designed to help you naturally master the overall flow of web development by directly creating Spring Boot projects commonly used in the industry. Rather than just explaining theory, you will follow a step-by-step process to build an actual project, gaining hands-on experience with core backend development concepts such as Controllers, Views, Services, Database integration, JPA, and ModelAndView. The course is structured to explain the project structure, data transfer methods, and DB integration processes—which beginners often find most difficult—as easily as possible, ensuring you understand not just how it works, but why. Even those starting Spring Boot for the first time can follow along without pressure through step-by-step explanations from the basics, allowing you to build a solid foundation for growing into a Java backend developer.

While studying Spring Security, you've probably wondered at least once: "I've built the login, but how do I handle authorization?" "How are authentication and authorization implemented in real-world practice?" This course is a practical, project-oriented lecture designed to solve those exact concerns. Instead of just explaining concepts, we implement them exactly as they are used in real services by: 👉 Building on an actual TodoApp project 👉 Integrating with a database 👉 Managing user permissions 👉 Handling validation In particular, I will provide easy, step-by-step explanations for the parts many students find difficult: Method-level authorization Access control within templates Validation using regular expressions Through this course, I will help you confidently say, 👉 "I can actually use Spring Security." 🚀

This course is a practice-oriented program where you will learn how to build a DevOps environment applicable to real-world services using Microsoft Azure and Azure DevOps. Rather than just explaining simple theories, the lecture proceeds step-by-step through the entire process of creating an actual project, integrating it with GitHub, and building CI/CD pipelines. Additionally, you will learn how to implement automated deployments in various environments using ASP.NET Core and Spring Boot projects. Learners will be able to understand and directly implement the entire DevOps workflow, from project management (Azure Boards) and source control (GitHub) to build and release automation (Azure Pipelines).

From the basics of the Spring Framework to practical usage! Become a developer who can be deployed and actively engaged in the field right away through thorough and comprehensive explanations and examples.

A practical Java-based Microservices Architecture (MSA) course that can be applied directly to real work! This course is a project-centered hands-on course on microservices for Java developers. Rather than stopping at simple theory, you can learn the core principles and implementation methods of microservices architecture through practice by following the actual service development flow.

This is an introductory backend development course where you learn through understanding rather than memorization, and experience rather than theory. Instead of reciting a Googled definition when asked "What is JPA?" in an interview, this course will empower you to give an answer based on experience, starting with "Well, I've been through JdbcTemplate hell..." You will gain a deep, intuitive understanding of "why we use frameworks" by experiencing firsthand how 30 lines of pure Java ServerSocket code shrink down to just 7 lines in Spring Boot. After 6 sessions, you will walk away with a functional portfolio piece: a Todo List REST API built with Spring Boot + JPA.

A Java advanced project course for beginner developers who want to develop practical skills! We'll build a console-based kiosk ordering system together using Spring Core, JdbcClient, and H2 DB.

It's time to master Java's various features so you can apply them in practice! ^^ Let's make it completely yours by solving algorithm problems together. Teacher Eun-jong will continue to be with you in Part 2.

In [Java Practical Project: UI Edition], we will create a movie information application that operates solely on pure Java technology using JavaFX. This course is designed to help you deeply understand the "structure connecting screens and logic" by directly implementing UI event handling, asynchronous logic, and user interaction flows in Java before moving on to web and smartphone apps. You will train your structural thinking by separating business logic and UI through integration with Spring Core, and learn how to solve UI performance degradation issues that may occur when fetching movie information from external APIs using asynchronous processing. Through this, you will clearly understand the principles of data flow, event listeners, and thread-based asynchronous processing, elevating your understanding of the Java language itself to the next level. In short, this course is a "practical stage to experience the essence of UI and the core of asynchronous processing with Java before moving to the web." Do not forget that this is not a class for just typing along with code, but a learning experience where you can personally master the principles of connecting UI and logic.

Through this lecture, you can learn about the characteristics and background of the Kotlin language, grammar and operation principles, usage examples, and things to be careful of when using Java and Kotlin together.

Are you using Java but still only utilizing Java 8 syntax? Discover the useful new features added in Java 11 LTS and become a more proficient developer by using Java more conveniently. The features introduced here can be used effectively in Java 11 LTS, 17 LTS, and 21 LTS versions.

Understanding Spring Boot + React.js Login (+Social) Service is a course designed to help you deeply understand the authentication flow between frontend and backend, by directly implementing a practical login system that includes JWT-based authentication and social login (Kakao/Google). The frontend is built on React.js, and the backend on Spring Boot, enabling you to learn step by step the practices used in real service environments, such as the Access Token + Refresh Token approach, user state management using HttpOnly Cookie and Redux, Role-based authorization, and social login integration.

Copilot used by working developers in the industry! From Copilot tips to unit testing and API integration testing, do it all with Vibe Coding! Leap forward as a 10x faster director with real-world industry know-how.

Beyond the basics of API design, CRUD implementation, and JWT authentication, all the way to backend architecture design! This is an introductory system design course to help you create 'your own backend architecture' so you can confidently discuss design experience in interviews.

This tutorial will show you how to use Bootstrap to create responsive web pages that change layout depending on the device.

Did you give up while studying Spring? Even complete beginners new to coding and non-majors can make it from JSP to Spring Boot without giving up - we'll open the path to Spring Boot for you.

Handling media (video, audio) on the web is now easier than ever! Learn the MediaStream API and WebRTC by following along step by step.

This lecture covers how to easily implement game backend systems using UGS (Unity Gaming Service). You will practice essential features such as Guest and Username/Password authentication, game data storage, leaderboards, and Remote Config. UGS has built a perfect ecosystem with Unity, preparing a practical course for easy learning without entry barriers, allowing immediate application to your projects.

Channel Talk interviewers will directly analyze the difference between failing and passing answers to the same question and help you prepare for actual follow-up questions.

This is a basic DFS lecture that explains the way a liberal arts major and working developer studied to get a job :) We have prepared a lecture where you can learn by solving problems yourself, with minimal boring theory lectures! After taking this lecture, you will be able to solve silver level DFS problems on your own according to Baekjoon standards.

An AI system that grades and reviews your code in 5 seconds - imagination becomes reality. This course is an all-in-one project that builds a **'GitHub PR Automatic Analysis and Grading Bot'** using Spring AI. When a student submits an assignment (Pull Request), the server detects it and AI analyzes the code changes (Diff). The grading results are then stored in the database, feedback is automatically posted as GitHub comments, and students can check their results on a dedicated dashboard. From backend to AI integration and frontend (Vaadin) - all with Java! This is the ultimate introductory guide for all developers who want to complete their own AI service from A to Z.

This course is for those preparing for coding tests in Java. It covers the top 10 topics that are most frequently tested in coding tests. It is structured step by step from basic to intermediate problems linked to the topic, so if you follow it step by step, you will get good results.

I have created an 'Introduction to Elasticsearch' course that is easy for non-majors to understand and can be applied immediately in practice!