From Java 9 to Java 21

Develop and deploy servers using Java, Spring Boot, JPA, MySQL, and AWS. While developing web applications, you will learn all the background knowledge, theories, and various technologies required for server development, as well as the meaning of various options, the history of Spring Boot, and the changes in the latest version.

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.

You will be able to understand all the language features of Kotlin. After taking the course, you will be able to freely program using advanced Kotlin technologies such as generics, delegation and deferral, DSL, and reflection.

We will refactor a web application built with Java + Spring Boot to Kotlin + Spring Boot and implement additional requirements. In the process, we will use Junit5, SQL, JPA, and Querydsl, and cover the pros and cons of various methods from the design and implementation perspectives.

Coroutine, the essential library for asynchronous programming! Learn the concept, usage, and internal principles of coroutines all at once!

The features added to Java 8 are widely used in APIs provided by Java as well as third-party libraries and frameworks such as Spring. If you are a Java developer in this era, you must know them. Make them your own technology easily and quickly through this lecture.

In this course, you will learn Kotlin syntax, how to safely convert Java projects to Kotlin, and how to code in a Kotlin-like manner. Learn Kotlin based on practical code and use it yourself to enjoy its advantages.

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

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

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.

This is a full-stack hands-on course where you'll clone ChatGPT and implement everything from scratch. From Spring Boot server to React frontend! This isn't just a course where you follow along with code, but one that guides you to build a high-quality AI chatbot service through actual service deployment.

What kinds of problems appear in coding tests these days? Solve “practical” problems yourself, reflecting the latest corporate coding test trends. We provide proven problems and solutions to effectively build your algorithm and problem-solving skills. (with Java)

A special Spring Boot meetup with Java Champion and Spring Developer Advocate Josh Long!

Let's learn object-oriented concepts through Java programming and improve program design and problem-solving skills!

Experience the power of Type Safe SQL with jOOQ!

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.

This course is a learning process that involves studying the fundamental theories of data structures by directly implementing them through JAVA programming. Rather than simply learning theory, it is structured to enable a deeper understanding of data structure principles by implementing them with actual code. Learners will theoretically learn core data structure concepts such as arrays, stacks, queues, lists, trees, and graphs, while simultaneously implementing them in JAVA code to experience their actual operation processes. Through this approach, rather than rote memorization, learners can develop logical thinking skills and problem-solving abilities, enjoying the synergistic effect of learning programming and data structures together. 👉 Upon completing this course, learners will master the basic concepts and structural characteristics of data structures, as well as the ability to implement and apply them in actual development environments, establishing a foundation for designing more efficient and robust programs.

This is an introductory Java course. It's easy.

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

Learn Java-based data structures and algorithms, and grow into a competitive coding expert with practical problems!

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, and database management, while also sharing insights on cloud integration, secure coding, developer performance improvement, and advanced development techniques. This conference is accessible to both professional and beginner developers, offering opportunities to learn about the latest technologies along with productivity tips for writing high-quality code more efficiently.

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

Refactoring is one of the basic skills that a software engineer should have. This course is designed to explain and practice various code smells and refactoring techniques in a more practical way using IntelliJ and Java.

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

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