Distributed data modeling

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

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

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.

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.

You can learn about the core functions of MySQL and how to effectively use them in your work. You can also gain a new understanding of important parts that you have been using for a long time and have overlooked, and gain in-depth database knowledge.

Make the most of relational database systems!

For learners struggling with large-scale data analysis and slow queries, I provide practical, hands-on guidance from design through tuning.

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.

"SQLD is an exam where past questions are not released." In preparation for the upcoming 62nd exam (2026.08.22)- Practical materials featuring 50 questions per subject and chapter, vividly reconstructed by directly recalling the latest 61st exam!

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.

You can solve design problems by writing code in a formatted way. You can understand code or patterns written by other programmers.

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

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.

Does game backend development feel daunting and vague? With know-how gained from firsthand experience with numerous projects, I will show you how to perfectly integrate complex Firebase features into actual games. We will connect Firebase to a Unity 6 Watermelon Game to implement online features such as login, cloud database (Firestore) save/load, rankings, bulletin boards, and mailboxes. This is a practical course that also covers security rules, Remote Config operations, and code design based on a layered architecture (UI, logic, and data access).

In the software system design course taught by Silicon Valley engineers, you will learn the design principles and architectural patterns of large-scale systems and how to build stable and scalable software solutions. In addition, you will cover performance optimization and fault response strategies through practical cases.

How does the architecture change when an LLM is integrated into an existing backend? This is an introductory system design course that goes beyond simple LLM API calls to help you understand core AI service components such as Model Routers, LLM Gateways, and Vector DBs, and step-by-step design an operational AI service architecture including RAG and AI Agents. It is designed to help those who want to create their own LLM-based AI services quickly master the design workflow.

Immutable truths for developers/engineers that will never change even in the AI era! We provide essential computer science knowledge for free to prepare for developer/engineer job applications and technical interviews.

This lecture comprehensively organizes the content that would be good for those who want to get a job as a new Spring Java backend developer, especially those who are about to have an interview.

If you can master DB and programming, you should be more than halfway prepared for the information processing engineer exam. Let's take a look at the DB and programming parts, which are worth 45 to 55 points in the practical exam, and pass the written exam steadily.

This course teaches you how to build a practical Unity game with a database. It covers difficult-to-access topics in an easy-to-follow lecture format.