A Working DBA Team Lead’s Design for Concurrent Inventory Decrements — How to Keep the Database Running Under Event Traffic

Solve the common codes, category hierarchies, history tracking, soft deletes, statistics, dynamic design, JSON utilization, and more that you inevitably encounter in real-world design through nine core patterns. This goes beyond simple theory, incorporating practical know-how proven across numerous projects and criteria for making the right choices in different situations. Become a true design expert who can confidently design for any requirement.

When faced with a single slow query, what should you look at, what should you fix, and how can you prove it? This hands-on, 55-lesson course teaches you by setting up a virtual online store with one million orders on your local MySQL 8.0 and working directly with EXPLAIN, EXPLAIN ANALYZE, and index design.

Learn database design systematically across three levels—conceptual, logical, and physical—and strengthen your skills through a practical, project-based e-commerce store. Gain hands-on expertise through modern design techniques and the latest trends.

We covered the concepts considered while migrating 20 billion data items managed through the existing MongoDB to MySQL.

Through the implementation of a first-come, first-served coupon system, you will solve key real-world backend challenges such as concurrency issues, data consistency, and handling peak traffic. By writing the code yourself, you will identify problems and master essential practical skills, including synchronous/asynchronous processing and queue management. This project-based course is designed to help junior developers and job seekers gain hands-on experience.

Make the most of relational database systems!

Let's edit and process the countless data generated through public services to build our own database, and discover another hidden world through a series of tasks that occur in the process and by utilizing SQL.

This course goes beyond basic CRUD-level database usage, helping you develop the PostgreSQL skills needed in the AI era from a practical, real-world perspective. Drawing on AI development experience in Silicon Valley, you’ll gradually learn how to design and use JSON, indexes, transactions, and pgvector in actual services, while gaining the skills to solve complex data structure and performance problems.

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

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.

Learn how modern data teams leverage dbt. Build maintainable analytics models and validated data pipelines hands-on. Master core concepts of analytics engineering with a practical focus. This course is for those who want to take their data career to the next level 🚀

A must-have subject for aspiring developers and those looking to get a job in big data!!

As you work in backend development, you eventually find yourself facing a certain concern. As services multiply and traffic increases, there comes a point when simple REST communication and a CRUD-only structure begin to show their limitations. I experienced the same problem in practice and went through many trials and errors trying to balance performance with structural complexity. The solution I chose in that process was NATS. Its simple, single-binary-based setup, ultra-low-latency performance measured in microseconds, and practical feature set—from Pub/Sub and Queue Groups to JetStream—made it a highly realistic choice for actual service environments. This course is not about listing NATS’s features. Based on the problems I encountered in practice, it explains through code and workflows when and why I chose NATS and how I designed the architecture. From those new to messaging systems, to backend developers preparing for employment, and senior developers considering better architectures, this course will help everyone understand distributed systems and grow to the next level.

From the fundamentals of MySQL usage to the advanced techniques required in real-world service environments, you will learn progressively. The course also covers a wide range of topics, including data modeling techniques based on various cases and practical data, evaluating the effectiveness of Foreign Key design, analyzing the Google Calendar schema DDL, and modern DDL design principles. It provides an in-depth understanding of how to use MySQL as a core component of a system, rather than merely as a database.

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

💆‍♀️I didn't know there was a course that explained Docker so easily... Now I know why I use Docker!

From Docker, Kubernetes to microservices, CI/CD, and service mesh, you can easily learn not only the basic theory but also the actual application implementation through examples. By organizing only the core contents necessary for actual use, it provides a starting point for learning about the element technologies covered in the lecture.

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 is a course for learning MS-SQL through baseball and corporate databases.

This course focuses more on data modeling through entity design than on JPA technical explanations. Based on the principle that solid DB design is the foundation of application development, we analyze various design patterns—such as one-to-many, many-to-many, inheritance, and collections—alongside business scenarios. You will learn by directly observing the process of code being transformed into actual tables on screen. To ensure immediate practical application, we provide business use cases, source code, and test codes for each design pattern.