The Easiest Concurrency Problem - Race Condition

Based on Oracle 21C, from concepts to practice, the easiest way to learn SQL for beginners! Taught directly by the author of Easyspub's "Do it! Introduction to SQL with Oracle"! Designed for non-majors and beginners, explained step by step.

This is a practical backend course designed to cultivate the service planning and design thinking skills that developers need in the AI era.

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.

Experience the power of Type Safe SQL with jOOQ!

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.

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

This course contains the essential content needed for those truly starting with Kubernetes (☸). 🧭 Through this course, you can begin understanding Kubernetes structure in the easiest way possible. 🥇

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

This is a SQLite lecture provided by Living Coding (Open Tutorials), which will help you get started with the relational database SQLite.

# Building an 'Intelligent Collaboration' Expert Agent Team Using Spring AI Router Pattern + RAG + MCP Beyond Single Agents to Architecture: The Definitive Guide to Router Pattern and Agent Isolation Design

I've created an 'Introduction to Elasticsearch' course that even non-majors can easily understand and apply directly in real-world situations!

I've created a 'Redis Beginner/Practical (Query Performance Optimization)' course that's easy to understand even for non-majors and can be applied immediately in real-world situations!

Learn SAGA transaction management techniques for maintaining data consistency in distributed environments through hands-on practice. Build 3 microservices using Spring Boot and Docker, and implement both Orchestration and Choreography patterns with Kafka and MySQL. Through this course, you can master core concepts that are immediately applicable in real-world scenarios, including distributed transaction operation principles, compensating transaction design, and failure recovery handling.

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 how to analyze 5 million Korean apartment transaction data using PostgreSQL. Covers the process of data cleaning, transformation, and deriving meaningful insights through various SQL queries.

This course is a practical-focused learning program for JWT-based token authentication and security enhancement techniques that are essential in modern web service environments. Using Spring Boot 3, Spring Security 6, and React, you'll implement secure login systems and cover comprehensive security practices including XSS·CSRF countermeasures, HTTPS implementation, token reissuance and revocation strategies, and secure secret key management. Additionally, you'll practice real service-level environment configuration through AWS build·deployment and performance optimization using Redis, and the complete project source code provided in the course can be directly applied to real-world work.

SQL data analysis! We will teach you how to solve practical problems that are applicable in the field, quickly and easily!

A beginner's guide to SQL coding! We'll teach you the secrets of writing, interpreting, and validating SQL.

By implementing various practical data analysis cases using SQL, you can simultaneously improve your data analysis and SQL utilization skills.

This is a full-stack hands-on course where you clone code ChatGPT and implement it from start to finish. From Spring Boot server to React frontend | Neo + Essential This isn't just a course where you follow along with code, but guides you to build a high-quality AI chatbot service through actual service deployment.