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 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.

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!

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.

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

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.

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.

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.

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.

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.

We will show you how Java backend developers using IntelliJ can maximize their productivity with Claude Code. In particular, we help you perfectly resolve the vibe coding environment issues faced by those using Windows environments.

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

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!

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

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

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 book contains only the essential techniques for those developing Windows OS-only applications using MFC.

This is a hands-on introductory course for AWS cloud beginners that follows and learns basic AWS cloud network knowledge.

This course is designed to learn the fundamentals of networks that form the foundation of the internet. It is structured to help you understand the basic concepts and structure of networks and systematically learn the principles of internet communication. Learners will acquire foundational theoretical and practical knowledge about networks, establishing a foundation for learning in the IT and information communication fields.

This course aims to build the complete understanding of Amazon Virtual Private Cloud (VPC) and Networking from grounds up where you will understand the AWS networking concepts to the depth not just theorotically but by actually performing hands-on exercises for all the networking components. This course will take your networking knowledge and experience to a level where you can confidently design and implement networking components on your own. And believe me, it's one of the most important skill to have to be successful in your AWS career.

[Reflecting the latest related regulations and guidelines presented by the Korea Financial Security Institute, Financial Supervisory Service, and Personal Information Protection Commission] In the rapidly changing digital financial environment, security has become not an option but a core survival strategy. This course covers the new directions of financial security changing with digital transformation, strategic response methods, and practical approaches to establishing a security culture within organizations. We will examine the policy directions of the Korea Financial Security Institute, the latest regulatory trends, and global security trends together, learning security innovation strategies centered on people and organizations beyond technology-focused approaches.

We introduce the basic knowledge of Hack&Hat analysis, a must-have subject to become a security expert.

Arduino? Coding? You don't need to know anything. Just invest a little bit of your free time and you'll find something amazing.

Learn about the network multiplayer framework, also known as the other Unreal Engine. Learn the key concepts, inner workings, and optimization techniques you need to know when creating a network multiplayer game, then create a hack & slash type PvP battle game.

[Introduction to Security Incident Response: Learning through Scenarios of Web Server Hacking, Ransomware, and Account Takeover] This course examines why various information security incidents—such as web server hacking, ransomware, account takeover, and internal penetration—occur and how they spread, categorized by incident type. Students will follow each incident scenario to understand the attack flow, analyze the core causes of the incident, and learn how to resolve issues and prevent recurrence through security architectures such as firewalls, DMZ, access control, privilege management, backup, and log monitoring. Rather than a simple explanation of security concepts, this is a scenario-based introduction to information security that provides a comprehensive understanding from root cause analysis to resolution strategies.

This course covers the basics of Amazon EKS, an AWS-managed Kubernetes service, designed for beginner Amazon EKS users.

The lecture explains why the harness is more important than the model through the Claude Code architecture. It covers how to design the Claude Code task system using six structures: Context Harness, Permission Harness, Verification Harness, Tool Harness, Subagent & Worktree Harness, and Debugging Harness. Afterward, it connects these concepts to CLAUDE.md, session management, large codebase control, worktree parallel operations, error log analysis, and tracking environment variables and configuration scope issues, establishing the standards for continuously using Claude Code in practical backend and DevOps workflows.

If you've been studying information security, you've probably had this thought at least once: "Firewall, CSPM, SIEM... I've heard the names, but I'm not exactly sure what they do." This course is designed to help beginners in information security clearly grasp the concept of the 'security solution landscape.' From the concepts and key features of each solution to their pros and cons, use cases, and the latest trends... With a total of 23 lectures, why not clear up the vagueness surrounding security solutions right now?

Network studies that you give up on every time because they are difficult and boring. Finish it once and for all with this textbook.

Non-Majors Welcome: Real-World Vibe Coding Projects Created Through Conversations with AI

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

It doesn't end with just following an example game. Through Vibe Coding, we will go through the entire process of an actual released project together—from game planning to development, mobile building, ad monetization, and registration on One Store, Google Play, and the App Store.

Are you tired of repetitive tasks? This one lecture is enough. Combine Make, Apps Script, and AI to build your own business automation system. From souvenir recommendations to receipt OCR processing, this is a practical, hands-on course where you just need to follow along, even if you don't know coding.

Creating a simple Omok game using Unity and a C# server

This is a practical course that uses Codex to connect business planning, website creation, marketing materials, task organization, and email automation. Even if you are not a developer, you will learn how to delegate tasks to AI and refine the results using Notion, Linear, Figma, and Google Workspace in an actual workflow sequence.

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.

Have you built screens and features with AI, only to get stuck on data structures, permissions, and changes? It’s okay if you have no experience with DB or SQL. We will improve a bulletin board from v0 to v7 by designing tables, relationships, constraints, redundancy, states, and ownership, and verify everything in Supabase from RLS to secure migrations. Even if AI writes the SQL, the rules and permissions of the data are decided by humans.