[Lv2] A Complete Guide to JPA for Professional Developers — From the Persistence Context to Practical Patterns

In a world where every résumé looks similar, “differentiation” gets you hired. Over six weeks, learn four practical résumé strategies directly from a backend professional.

This is a [Backend, Resume Enhancement] class prepared for job seekers and junior developers.

It covers just two things properly: object-oriented programming and the JVM! Plus, it throws in linked-list-based linear data structures.

Learn Java generics and collection frameworks in depth with a focus on practical applications. Also learn the basics of data structures.

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.

A Channel Talk interviewer will personally break down the difference between rejected and accepted answers to the same question and prepare you for real interview follow-up questions.

Software development roles in the defense industry: ✔ Have different hiring criteria compared to general IT companies ✔ Use specialized tech stacks and development methodologies ✔ Offer very little information on how to effectively highlight your major, career, and projects. This course: 👉 Provides the perspective of a software developer who has experienced actual defense projects and hiring processes 👉 Explains how defense companies evaluate software developers 👉 Focuses on specific case studies to show you how to prepare your resume, interviews, and projects to increase your chances of success. This course transforms the state of "wanting to become a defense software developer but having no idea what to prepare" into a "clear roadmap you can start following right now."

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

After using it for 14 days starting immediately upon release, here are the reasons why I recommend Claude Code (AI Coding) to everyone—from job seekers to industry professionals—as something they can apply right away.

This course focuses more on data modeling through entity design than on JPA technical explanations. Based on the principle that solid DB design is the foundation of application development, we analyze various design patterns—such as one-to-many, many-to-many, inheritance, and collections—alongside business scenarios. You will learn by directly observing the process of code being transformed into actual tables on screen. To ensure immediate practical application, we provide business use cases, source code, and test codes for each design pattern.

Learning about various communication techniques and understanding their differences helps you develop the ability to select and implement the most appropriate communication method.

When fixing legacy Java code, determine what to change and which behaviors to preserve. In the existing IntelliJ IDEA hands-on exercises, you directly review code changes, while in the 16 newly added theory lessons, you learn about names, functions, duplication, responsibilities, calling contracts, and validation criteria.

Why do requests wait when queries are fast? Locks. In a hands-on project using MySQL 8.0, Spring Boot, and JPA, reproduce record and gap locks, four types of deadlocks, long transactions and connection pool exhaustion, metadata locks during deployment, and lost updates with tests. Then fix them in code and verify the fixes with the same tests.

Just listen. The lecturing skill, captivating power, and lecture quality are different.

A mediocre developer portfolio won't get you hired! Revealing the portfolio secrets that actually landed jobs at major IT giants like Kakao, Samsung Electronics, and Naver!

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.

I highly recommend Spring AI to developers using Spring Boot and React, as well as those considering the introduction of AI systems in corporate environments. This course goes beyond a simple introduction to libraries; it helps you understand the core concepts and internal structure of Spring AI, and strengthens your practical implementation skills through various hands-on examples. The course is based on Spring AI version 1.1.x and provides continuous technical support and expansion strategies to ensure you can adapt to future version upgrades. Furthermore, we expand the practical value of Spring AI technology by utilizing MCP (Model Context Protocol) to achieve cross-domain context integration, AI linkage in distributed environments, and AI architecture design suitable for enterprise environments. With the goal of building AI systems that can actually be deployed in corporate settings, this will serve as a practical guide that balances theory and hands-on experience.

Learn the basic, essential, and practical knowledge of Kafka that software developers need to know. We will integrate Kafka using Spring Boot and conduct hands-on exercises for sending and receiving messages tailored to various real-world scenarios.

This course was created based on my personal experience passing the very first revised Information Processing Engineer practical exam, which had a pass rate of only 5.34%. The Information Processing Engineer practical exam can no longer be prepared for through simple memorization alone. In particular, the ability to read the execution flow of C, Java, Python, and SQL code to track results, as well as the ability to accurately distinguish short-answer concepts and write them as answers, has become crucial. This course is structured to help even beginners who are new to programming follow along step-by-step, covering everything from creating variable tables to tracking C, Java, Python, and SQL code, core practical terminology, and written exam subjects 1 through 5. Rather than being a video-centered course, this is a text-based course designed for fast reading and repeated review. It makes it easy to look up necessary parts again and focuses on practicing how to derive answers at the testing center by following the code and explanations directly. The 1st update covers the practical programming sections: C, Java, Python, and SQL. The 2nd update will organize core terms and concepts required for the short-answer practical questions and provide a "Stepper Simulator" to practice code tracking directly. The 3rd update will sequentially expand to cover written exam subjects 1 through 5. The Stepper Simulator is designed so that you don't just stop at reading explanations; you can understand how variable values change as the code executes line by line by following along yourself. If you have any questions while taking the course, please leave them in the Q&A. I will respond as quickly as possible to ensure your learning doesn't get stuck.

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