The Easiest Concurrency Problem - Race Condition

Make the most of relational database systems!

I will transform the Engineer Information Processing written exam (Subjects 1–5) from a "test you solve by memorizing" into a "test where you connect clarified points directly to your score." This is an ultra-compressed lecture designed to help you grasp the entire flow within 3 days. It extracts only the core concepts repeated in past exams, structured to be understood even if viewed right before the test. The course is designed for short-term success by clearly distinguishing between frequently confusing concepts, trap points in multiple-choice options, and what needs to be memorized versus what only needs to be understood. "I'm short on time, but the scope is too broad." "I feel like I know the material when reading the book, but I keep getting the questions wrong." This lecture is for students facing these exact challenges.

This course was created for those who find databases challenging, making it easy to understand concepts and build your skills through practice. This lecture covers database fundamentals and SQL language usage. For learning how to create databases, you can take the database design course. Since most program developers encounter databases in their work, I've made an effort to explain in detail how to approach databases from a programmer's perspective.

This course does not teach the grammar of C#. It simply uses C# as a tool for designing object-oriented programs. This course covers in depth the essential content that intermediate and higher level programmers need to know, as well as the content that is essential to developing programs that are linked to databases.

This course proceeds in stages where you learn and apply necessary knowledge while building infrastructure, similar to real-world practice.

Copilot used by working developers in the industry! From Copilot tips to unit testing and API integration testing, do it all with Vibe Coding! Leap forward as a 10x faster director with real-world industry know-how.

This course is an easy-to-understand explanation of database design theory, focusing on practical exercises. Most people who have experienced it through books, etc. have probably felt that database theory was difficult and given up. I did the same. However, if you know it, you will find that it is an easy and very interesting field. In this course, the design content is organized so that you can understand it just by looking at it.

Drawing from my own experience of feeling despondent when trying to implement practical code during my first MSA transition—despite knowing the theory—I will help you grow into a developer who guarantees perfect data consistency amidst any system failure by directly rolling back daunting compensation logic through 9-step practical patterns and AI Agent coding.

Developing an 'Autonomous' Premium Reservation Agent Backend Using Spring AI + JPA + MySQL Beyond Chatbots to Agents: The Standard of Tool Calling and Prompt Engineering

A Redis course created with a current Kakao interviewer. From hands-on practice with data structures ranging from String to Sorted Set to Sentinel and cluster configuration, you’ll build design rationale that holds up in interviews and real-world work.

In this course, you will be able to create a Reddit website from scratch, step by step.

Understand multithreaded programming and see how this knowledge can help you analyze other projects.

The most definitive practical guide for developers who want to integrate AI into their Spring projects right away! Beyond simple LLM API calls, you will perfectly master building production-level AI environments that can be immediately applied to real business logic using RAG and MCP.

Understanding Spring Boot + React.js Login (+Social) Service is a course designed to help you deeply understand the authentication flow between frontend and backend, by directly implementing a practical login system that includes JWT-based authentication and social login (Kakao/Google). The frontend is built on React.js, and the backend on Spring Boot, enabling you to learn step by step the practices used in real service environments, such as the Access Token + Refresh Token approach, user state management using HttpOnly Cookie and Redux, Role-based authorization, and social login integration.

Learn common components of global-scale services through popular papers, books, and articles.

I learned it the hard way, but I want you to learn it easily. I've discarded unnecessary theories and included only the core essentials of SQL. Build your SQL confidence quickly.

Regardless of the field! This is a lecture that covers the core fundamentals that developers must know in practice in an easy + code-oriented way. I highly recommend this lecture to all junior developers and job seekers who want to grow.

This covers what you need when you’re just getting started with Kubernetes (☸). 🧭 Through this course, you can begin learning Kubernetes while understanding its architecture in the easiest way possible. 🥇

Building an 'Intelligent Collaboration' Expert Agent Team Using Spring AI Router Pattern + RAG + MCP Beyond a Single Agent to Architecture: The Standard for Router Patterns and Agent Isolation Design

I have summarized the essential SQL SELECT statements and basic usage of Google Sheets that I learned while working as an analyst at a service company.