Intermediate PostgreSQL in Practice: Data Modeling, Tuning, and Analysis of 5 Million Apartment Transactions

From SQL basics to practical analysis! Learn powerful SQL skills to solve business problems by extracting, transforming, and analyzing data.

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.

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

A DBA instructor with 30 years of experience teaches 45 essential SQL tuning techniques that can be immediately applied in practice through real-world examples. Master the practical know-how to make slow queries 10 times faster, from execution plan analysis to index optimization and join tuning!

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.

Through detailed lectures and hands-on practice on the core elements of SQL, we will provide you with a solid foundation to grow into a SQL analysis expert.

Learn how to model data in a distributed database environment.

This is a code-lab-oriented course where you will directly build big data or distributed processing system clusters (HDFS, Zookeeper, Spark, Zeppelin) that guarantee High Availability.

Learn the core functions of SPSS in a short period to pass the Social Survey Analyst Level 2 practical exam. Master SPSS know-how along with problem-solving techniques—ranging from data entry to descriptive statistics, cross-tabulation, t-tests, ANOVA, and correlation/regression analysis—to perfectly prepare for the practical exam.

Channel Talk interviewers will directly analyze the difference between failing and passing answers to the same questions, and help you prepare for actual follow-up questions.

"Data analysis—don't stay trapped in complex Python syntax and Excel functions anymore." This course is a practical masterclass that automates the entire process of data processing, from Excel and Google Sheets to Python-linked analysis, by hiring the latest AI agents as your own dedicated data analysts. Instead of difficult coding knowledge, we introduce the latest 'Vibe Coding' method—commanding as if having a conversation in natural language—allowing even non-majors to enter the world of data analysis without any barriers. Through comprehensive hands-on practice using actual business data—covering everything from data preprocessing and visualization to report writing—experience a powerful AI workflow that you can apply to your work starting tomorrow. A lecture utilizing AI agents, Excel data analysis, chatGPT, Gemini, (Python), Genspark, Google Colab, chatbots, Google Antigravity, and notebookLM.

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

Revolutionize your stock investing with AI! In this course, you’ll build a fully functional AI automated trading system that targets the top 25 Nasdaq stocks. Gain experience and know-how through paper trading with the Korea Investment & Securities API, and take advantage of this special opportunity to conduct AI-powered automated stock trading with a real account. Even if you’re a complete beginner, there’s no problem. We’ll explain the basic concepts of stocks and why you should invest in U.S. stocks in an easy-to-understand way, and provide all source code along with remote support. From now on, investing is essential for the next 60 years of our lives. Build your own AI investment partner to accompany you!

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 🚀

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

Repetitive pipeline management in Data Warehouses (DW), now free yourself from that painful cycle with dbt! Building on the efficiency provided by dbt, become a data analytics engineer who creates higher value through business-centric data modeling, effective data lifecycle management, and more.

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.

Learn how to use AI tools to strategically analyze raw data and visualize it persuasively—without complex or tedious statistical or coding knowledge. Starting with preprocessing messy raw data, you’ll complete complex tasks such as exploratory data analysis (EDA) and correlation analysis through just a few AI conversations, dramatically reducing the time required for practical analysis. Through concise, hands-on theory and scenario-based exercises, develop your own end-to-end professional skills for transforming numbers into powerful tools of business persuasion.

Is it enough to just search for past exam questions and pass the Google Analytics Individual Qualification (GAIQ)? A certification holds little meaning if you obtain it without knowing how GA4 is actually used in practice or how to query and utilize data. This course focuses on practical application, allowing you to directly examine reports and GA demo accounts, and even set up a demo shopping mall yourself. You will build the skills necessary for the field while solving the latest 2026 GAIQ exam questions.

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.