Essential Computer Science Knowledge for Job Preparation

From building a database to creating tables, you can manipulate and change data within the database using various SQL queries.

You can master Database development, which is essential for mobile/web development, through MySQL.

This course focuses on building the real skills needed in actual development work. The goal is not simply to learn how to write code well, but to experience how to work well as a developer. The examples are based on the commerce domain, covering cases frequently encountered in real-world work environments, and are provided in SpringBoot & Kotlin. However, it's a course where anyone can contemplate and experience real-world development through thought-provoking content, without being dependent on any specific language or framework. Based on the practical perspective of a senior developer and former director at Toss Payments who led a large-scale payment service organization, the course is designed to help you learn the thought processes and design decisions used in actual work environments.

When Redis alone can no longer guarantee performance, what options do we have?? There is Valkey, which is 100% compatible with Redis and applies IO-based tuning. Through this course, let’s explore how Valkey guarantees 1M++ TPS and learn about the data structures suited to different traffic patterns and feature implementations.

Programming is a science of logic and reason. Data structures are essential for more independent thinking and active coding. This lecture is designed to explain various terminologies and concepts for non-majors. Based on the actual content taught in offline classes, you can learn about the types and characteristics of data structures through simple code design.

MySQL for non-majors! This lecture quickly skims through essential concepts with brief explanations, then allows you to learn MySQL hands-on by "playing" with examples on the site.

[Only for those new to web development] Spring Boot REST API: Building step-by-step while properly understanding JPA

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!

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.

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

This course covers essential content that C# application developers with 0.5 to 3 years of experience must know.

Hashing, salting, JWT, symmetric and asymmetric keys, and even HTTPS and TLS. The backbone of security that we use every day yet always found vague and unsettling. If we have to face the countless neglected threats and technical debt someday, let’s properly tackle them once and for all this time.

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

This is an all-in-one curriculum for game programming beginners who are unsure of where to start. It is a comprehensive curriculum that covers the basics of game programming, including C++, data structures/algorithms, STL, game mathematics, Windows API, and an introduction to game servers.

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.

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.

From HTTP basics to data requests, real-time communication, security, and performance optimization, learn the network knowledge web developers must know.

In an era when AI writes code, developers need the ability to determine why that code becomes slow and where it can go wrong. From the basics of CPUs and threads to the principles behind running multiple tasks simultaneously, you’ll build your understanding step by step through hands-on exercises, detailed notes, and simulations. Based on this foundation, you’ll learn to identify the causes of performance problems and develop the fundamentals for designing fast, reliable 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!

Through this course, students will learn the overall concepts of data structures.