We have gathered all the essential network theories that those planning to operate services in an AWS environment must know. Through this course, you can understand the principles of how AWS VPC (Virtual Private Cloud), composed of private networks using Private IPs, works and gain a detailed understanding of the roles of services such as ALB and NLB.

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!

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!

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.

This is a practical project course where you will build a complete web service from planning to deployment using AI coding tools. You will gain hands-on experience with the entire process—including database design, file storage implementation, and service operation—within a Windows environment to acquire practical development skills for the AI era.

From AWS EC2 backend operations to automatic error fixing, we are revealing the entire development process of Sidabari (https://github.com/cx8537/sidabari), a Claude Code-based automation tool. In this course, we provide all the actual prompts and conversation history used as learning materials, allowing you to experience the entire prompt input process involved in its creation.

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!

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.

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!!!

From TCP/IP to HTTP! This course is prepared for those who lack basic network theory but hope to understand major-level concepts, even if it means "memorizing" them. You can do it!

This course is provided for those who have completed the 'Becoming a CS Major by Memorizing Broadly and Shallowly' course to study operating systems in greater depth.

This course summarizes the essential concepts you must know before learning any programming language. Furthermore, by practicing with a dedicated training system, anyone can easily acquire the critical thinking skills necessary for programming.

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

We will conduct an in-depth analysis of major domestic security incidents, such as personal information leaks from mobile carriers, the March 20 cyberattack, and the hacking of the Blue House. By examining the causes, damages, and response processes of each incident, we will understand the security threats facing modern organizations and individuals and learn practical prevention and response strategies.

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

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.

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!

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!

Secrets to Escaping Beginner Status Revealed! We'll properly teach you about Java multithreaded programming and synchronization techniques!

If you study the main concepts of Linux, you can handle Linux more easily and more powerfully. I hope you build a solid foundation from the beginning!! :D

The lecture focuses on how to use Docker in Swarm mode. It guides beginners to easily build and operate servers.

This 'Core Practical Linux' course is designed for those new to Linux, as well as those looking to enhance their practical Linux skills. It covers core basic Linux content and focuses only on essential and frequently used features from a backend developer's perspective.

This is a 'Practical Linux Troubleshooting Course' where you analyze and solve problems together with generative AI, based on a Docker practice environment that reproduces 5 representative failures that occur in actual Linux operating environments. Even those who were overwhelmed about where to start examining problems can learn the problem-solving approach and thought process of field engineers through AI guidance.

We will develop a MSA delivery application using Docker, Docker compose, and Traefik server. In addition, we will systematically learn theoretical knowledge such as MSA, Proxy Server, Load Balancer, API Gateway, etc. that are necessary for development. All learning courses are composed of practical training, and through this, you will gain confidence in developing Docker-based applications.

This course does not simply list concepts. 👉 It explains the entire flow of IT systems based on "how a service actually operates." User Request → Server Processing → Data Storage → Result Return Web/App → API → DB → Cloud 👉 Centered around this flow, it connects where, why, and how each technology is used.

This is a course to comprehensively understand 5G networks. We will look at the evolution from 1G to 5G and learn about the characteristics and architecture of networks including 5G RAN and 5GC.

Now I can analyze the Linux kernel too! The easiest kernel lecture among all Linux kernel courses.

Systematically learn Docker, a core tool for container-based application deployment, from the basics to practical application. Starting with Docker's basic structure and commands, you will develop practical skills that can be immediately applied to real-world tasks, including container packaging in microservices architecture environments, deployment automation, and standardization of production environments.

This course is designed to help you quickly learn server deployment methods using Nginx, Docker, and Spring Boot through hands-on practice. Learn Blue-Green deployment, a frequently used technique in the industry, faster than anyone else!

This course covers how to use Linux. The part that beginners find particularly difficult is how to control the computer using commands. This course covers the most common rules that beginners need to use commands.

This course focuses on solving the problem of getting stuck in interviews and practical work due to a lack of understanding of why certain structures and configurations are necessary, rather than just teaching how to configure NGINX. Based on experience evaluating numerous candidates as an interviewer for companies like Naver, Kakao, and Toss, I explain how to describe and utilize NGINX from the perspectives of performance, scalability, and operations through hands-on practice. The core of this course is to help you develop a mindset capable of tracing traffic flow and troubleshooting problems, rather than just memorizing configuration values.

From Theory to the Field: Proving Core Competencies of a Security Expert through Wazuh+ELK SIEM Implementation Design and operate a Threat Hunting system, the core of security monitoring, firsthand. Through hands-on practice based on real-world attack scenarios, transform into a professional security engineer capable of delivering immediate results in the field.

I have created a 'Linux for Beginners' course that is easy for non-majors to understand and can be applied in practice immediately!

✅ Out of the entire series (1) ~ (7), (5) operating system, user interface, database ✅ CS101 series lectures - From basic computer theory to the latest practical examples - Provides a wide range of basic knowledge

You can quickly experience the process of deploying a sample e-commerce service to AWS and continuously improving it into a robust and efficient environment.

This course is provided for those who have completed the 'Becoming a CS Major by Memorizing Broadly and Shallowly' course to study operating systems in greater depth.

This course is designed for developers, DevOps engineers, cloud engineers, and IT professionals who want to master advanced Kubernetes concepts used in real-world production environments. Throughout the course, students will engage in hands-on projects and real-world deployment scenarios, learning how to build secure, scalable, and production-ready Kubernetes infrastructure. Rather than focusing solely on theory, this course emphasizes practical implementation, troubleshooting, and best practices utilized by modern DevOps teams. One of the biggest challenges students face when learning Kubernetes is understanding how all components interact within large-scale environments. Many learners struggle with topics such as RBAC permissions, persistent storage, namespaces, network policies, StatefulSets, Kustomize, and secure cloud deployments. This course addresses these issues step-by-step through clear explanations, guided labs, and examples that mirror actual production environments. Students will learn step-by-step how to organize Kubernetes resources, secure workloads, manage application configurations, deploy stateful applications like MongoDB, and automate multi-environment deployments using Kustomize. Additionally, the course covers how to deploy applications to Google Kubernetes Engine (GKE) and configure Ingress, TLS certificates, monitoring, and scaling strategies. By the end of this course, students will have the confidence to design, secure, deploy, and manage advanced Kubernetes environments used in professional DevOps and cloud engineering workflows.

A course where you understand core operating system concepts and train to explain them verbally for interviews.