High-Performance JPA & Hibernate

Make the most of relational database systems!

Even people who are studying Java for the first time can easily understand it. You'll learn Java through theory with rich explanations and hands-on practice.

For those who are new to JPA or who use JPA in practice but lack basic theory, By learning the basic theory of JPA solidly, even beginners can confidently use JPA in practice.

For those aspiring to be Java-based Spring backend developers, to easily secure a job, we learn Java properly! Rigorously!

You can improve your Java programming skills by working on your own projects using various Java APIs and Open APIs.

Experience the power of Type Safe SQL with jOOQ!

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

If you were to ask me which programming language is most used in companies, I would say Java. Let's have fun learning Java with fun Java education.

When you're doing backend development, at some point you face this dilemma. As services grow and traffic increases, there comes a moment when simple REST communication and CRUD structures feel limiting. I experienced the same problem in real-world work and went through many trials and errors between performance and structural complexity. The solution I chose in that process was NATS. Its simple configuration based on a single binary, ultra-low latency performance in microseconds, and the fact that it provides just the right amount of essential features for real work—from Pub/Sub to Queue Groups and JetStream—made it a very practical choice in actual service environments. This course is not about listing NATS features. Based on the problems I faced in real work, I explain with code and flow diagrams which situations led me to choose NATS, why, and how I designed the architecture. This is a course designed to help everyone—from those new to messaging systems, to backend developers preparing for jobs, to senior developers contemplating better architectures—understand distributed systems and grow to the next level.

A practical course on easily building a super simple bulletin board with Spring Boot and React.js! This course focuses less on theory and more on hands-on practice, covering the web application development process for quick completion.

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

This is a full-stack hands-on course where you clone code ChatGPT and implement it from start to finish. From Spring Boot server to React frontend | Neo + Essential This isn't just a course where you follow along with code, but guides you to build a high-quality AI chatbot service through actual service deployment.

Learn Springboot + Android(Compose) RestAPI Board Creation Faster Than Anyone Develop a CRUD server with Springboot and create your own board with Android!!

Learn Springboot + iOS RestAPI Board Creation Faster Than Anyone Develop a CRUD server with Springboot and create your own board with iOS!!

Spring AI + JPA + MySQL Premium Reservation Agent Backend Development with 'Autonomous Behavior' Beyond Chatbots to Agents: The Definitive Guide to Tool Calling and Prompt Engineering

IntelliJ IDEA Conf 2025 is an annual online conference hosted by JetBrains that provides valuable sessions for Java and Kotlin developers. It covers various topics including AI adoption, Spring Boot, Gradle, Kafka, database management, and also shares insights on cloud integration, secure coding, developer performance improvement, and advanced development techniques. This conference is open to both professional and beginner developers, offering opportunities to explore the latest technologies along with productivity tips for writing high-quality code faster.

Complete a project integrating an API server built with Spring Boot (Spring Boot ver3.4.x) and React 19 (with TypeScript)! Apply a front-end to your backend portfolio! A course designed for working professionals (not for beginners).

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 structured to help you learn Redis's basic commands using Lettuce, one of Java's official libraries, and to understand how to handle Redis at a low level.

Learn how to save, modify, delete, and query data in a database. Anyone, regardless of major, can easily follow along in just 30 minutes.

If you can master DB and programming, you should be more than halfway prepared for the information processing engineer exam. Let's take a look at the DB and programming parts, which are worth 45 to 55 points in the practical exam, and pass the written exam steadily.