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)

The fastest way to build the foundation of coding tests for joining IT companies! #Picture-based explanation #Code writing know-how #Companies you can go to #Only necessary 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.

Through this course, you can learn how to run Java applications more efficiently and effectively solve performance issues that may arise.

Build your coding skills by implementing data structures in Java from the ground up.

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.

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.

Scala allows you to write much more concise and robust code quickly, while still leveraging the experience you have gained as a Java developer. This course is designed for Java developers to quickly understand the overall look of Scala based on their existing Java knowledge. If you are an existing Java developer, you can learn Scala very easily.

Through the 25 patterns of OODP, you will learn various ways to design software in an object-oriented manner.

When learning Swift, the iOS programming language, it can be confusing when multiple concepts appear all at once. That's why I created this course with the principle that "when understanding a new concept, only previously learned concepts should be used." So this course is meticulously designed with a sequential structure between concepts, where only one new concept appears at each stage, and no other unfamiliar concepts appear at all. One concept per minute, 180 concepts total. From the basics of variables and constants to understanding memory structure from a CS perspective, and even the latest syntax for asynchronous processing. In 3 hours, you'll learn 180 core concepts in the designed order.

Build a scalable real-time event streaming order processing system using Spring Boot 3.x + Kotlin, establishing a Kafka cluster, and leveraging PostgreSQL CDC, Debezium Connect, and Apache Avro schemas.

This course is a process of learning the basic theories of data structures by directly implementing them using JAVA programming. It is designed to go beyond simply learning theory, allowing you to gain a deeper understanding of the principles of data structures by implementing them with actual code. Learners will theoretically study core data structure concepts such as arrays, stacks, queues, lists, trees, and graphs, while simultaneously experiencing the actual operation process by implementing them in JAVA code. Through this, you can develop logical thinking and problem-solving skills rather than simple rote learning, and enjoy the synergistic effect of mastering both 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 real-world development environments, building a foundation for designing more efficient and robust programs.

[The 2nd edition is scheduled for completion in 2026] Presents various clean coding techniques.

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.

Knowing design patterns will make it easier to learn not only Spring but also many other technologies and programming languages. It will also help you develop more flexible and reusable object-oriented software.

This course is for those preparing for the CosPro Level 1 exam, covering the COS Pro Level 1 sample problems released by the exam organizer, YBM Net Co., Ltd.

Non-majors and beginner developers can easily learn Java grammar. It is a method of learning grammar by analyzing examples.

Learn the process of application development/release/update all at once through the Android Brainwashing Classroom. Learn the basics of JAVA and learn the distribution and update process while actually building an Android app. Implement the core functions of In★Gram yourself through practice. You can get started even if you don't know programming.

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.

When learning Swift, the iOS programming language, it can be confusing when multiple concepts appear all at once. That's why I created this course with the principle that "when understanding a new concept, only previously learned concepts should be used." So this course is meticulously designed with a sequential structure between concepts, where only one new concept appears at each stage, and no other unfamiliar concepts appear at all. One concept per minute, 180 concepts total. From the basics of variables and constants to understanding memory structure from a CS perspective, and even the latest syntax for asynchronous processing. In 3 hours, you'll learn 180 core concepts in the designed order.