Solid Foundation! Starting Java with Determination - Part 1: Procedural Programming

Design a modern 3-tier web service with AI and develop it using only "Vibe Coding," then deploy it to an AWS environment to complete a fully functional production service! We have included the entire sequence of configuration processes so you can experience core AWS services used in the industry—such as Amplify, CloudFront, ALB, EC2, S3, and RDS—in a single workflow.

From TCP/IP to HTTP! This lecture is for those who lack basic network theory and want to understand major theories by memorizing them. You can do it!

This is a C programming course for those who wish to pursue a path as a professional developer rather than just a hobbyist. I recommend this to those who are willing to learn through bitter and rigorous study to reach a sweet destination!

Are you lost while learning web development? I'll help you find your own way. Even if you're not from a computer science background, you can understand how web service architecture works through a short 1-hour lecture.

This is a lecture for all non-major beginners who want to become computer science majors by memorizing broadly and shallowly. You can quickly learn what you can learn in essential computer science major subjects such as computer architecture and operating systems. Above all, you can finish it by memorizing it!

We will help you memorize and finish the encryption technology responsible for the security of the Internet very easily. You can understand the structure and principles of various technologies such as SSL certificates, PKI technology, digital signatures, and public authentication systems.

This is a course provided to those who have completed the course 'Learn broadly and superficially to become a computer science major' so that they can study the operating system in more depth.

A must-take course for anyone thinking of becoming a Windows programmer! Have you studied C/C+, data structures, and operating system theory? If so, studying system programming is the answer now. Now it's time for practice!

This lecture guides those who have learned the basic course of network core theory by memorizing it to understand theories in more depth. It covers more in-depth theories such as NAT technology, the operating principle of Internet routers, load distribution system principles, and VPN technology principles. The goal of this lecture is also to finish it by memorizing it! You can do it!

I'll show you how Java backend developers using IntelliJ can maximize productivity with Claude Code. In particular, I'll help you completely solve the Vibe coding environment issues that Windows users experience.

Starting with java.io, you can learn how to develop high-performance input/output systems based on NIO and NIO.2. Most importantly, the moment you master file I/O, we'll enable you to master high-performance server development as a bonus!

This course covers topics for those who have completed basic studies of the C language, such as compiler theory, stack frame structure, multi-threading, virtual memory structure, security vulnerabilities, and secure coding. It is highly recommended for those who wish to become experts in the C/C++ field, or those who majored in CS or have similar skills!

We enable you to fundamentally understand and resolve issues where Hangeul appears broken on web pages or in databases, or files contain unknown characters.

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

Based on an understanding of Reflection and Annotations, it helps you clearly understand how the Spring framework operates!

This lecture covers how to properly implement a linked list-based linear data structure using C language. You can understand the structure of the DB as well as the linked list at once.

If you have studied the C language thoroughly and studied linear data structures, it is now time to experience the world of object-oriented programming with C++!

You will acquire the skills to develop a security system by learning how to intercept the process in which a specific application calls various API functions. ※Absolutely no abuse!!!

This course is for those who want to develop packet analysis programs like Wireshark and various network solutions using the Npcap library.

This lecture comprehensively organizes the content that would be good for those who want to get a job as a new Spring Java backend developer, especially those who are about to have an interview.

Starting with java.io, you can learn how to develop high-performance input/output systems based on NIO and NIO.2. Most importantly, the moment you master file I/O, we'll enable you to master high-performance server development as a bonus!

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

This is the first lecture of Clean Spring, a lecture series designed to allow a hypothetical startup development team to experience, in a manner similar to actual work processes, the process of developing quickly, stably, flexibly, and with good maintainability by incrementally following Clean Code and Spring development principles. By utilizing Domain Model Pattern and Hexagonal Architecture, you can acquire necessary skills and development strategies in the domain-centric initial development phase.

This course covers how to set up multi-module projects from scratch using Kotlin and Spring Boot. It proceeds with a hands-on approach, covering everything from the basic concepts of modularization to Gradle configuration, managing dependencies between modules, and actual application development. If you are a beginner or intermediate developer looking to learn the fundamentals and practical application of multi-modules, please refer to this course.

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

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.

Experience the power of Type Safe SQL with jOOQ!

Learn the essential modern Java technologies of Lambda, Stream, and functional programming with Java, from the basics to the practical level, in depth.

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.

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

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

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.

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

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.

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.

The TDD & Clean Code masterpiece lecture, recommended by many senior developers in Korea to junior developers for over a decade.

This is a lecture for people who are starting development for the first time. It's about programming thinking, which should come before development languages or UI frameworks.

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.

OODP's 25 patterns teach various methods for object-oriented software design.