Building a Stateful Service for Large-Scale Chat TPS

You can learn about implementing webcam and peer-to-peer communication using WebRTC.

This lecture covers the process of configuring a custom Gateway API using yaml.

In this course, you will learn how to create a Discord Bot. You can learn from simple messages to complex complexes.

We will inform you about all the security aspects of migration using MySQL and direct operation of DB Server.

In this lecture, you will learn how to use OpenTracing to perform distributed tracing across various applications.

We will inform you about the platform mass adoption method using AWS (S3, CloudFront) and MySQL (Geospatial Query).

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

In this lecture, we aim to create a Web Scraping API server using the Naver Shopping site. We will show you how to configure a managed API server by connecting MySQL and configuring a 3-tier architecture!!

This is a lecture about learning WebSocket communication for chat servers used in streaming platforms and actually implementing it.

In this lecture, we will discuss how to reduce resources for server-to-server communication by implementing RPC and gRPC communications used in actual practice.

This is a content about backend development using two databases, MySQL and Mongo, for job seekers preparing for backend employment.

In this lecture, we will actually implement the core module of the blockchain indirectly through code. Through this process, you can learn in detail what the blockchain is and how it works. Actually, as someone who studies blockchain and works on blockchain-related tasks, most lectures focus on theoretical content or on using some functions called smart contracts. I wanted to make a difference from these lectures, so I prepared it so that you can indirectly create the core module by following my lectures one by one.

You will learn how to write queries against large amounts of data using MongoDB.

It covers not only how to configure CRUD using Golang, but also how to use PostMan when collaborating with the front-end, and even repository management and environment construction! It contains the knowledge necessary for actual work.

You will learn how to write queries against large amounts of data using MongoDB.

We will inform you about all the security aspects of migration using MySQL and direct operation of DB Server.

This course provides a step-by-step learning path, ranging from the fundamental usage of MySQL to advanced techniques required in real-world production environments. It covers a wide range of topics, including data modeling techniques based on various case studies and practical data, evaluating the effectiveness of Foreign Key designs, analyzing Google Calendar schema DDL, and modern DDL design principles. Through this course, you will gain an in-depth understanding of how to utilize MySQL as a core system component rather than just a simple database.

This course goes beyond simple CRUD-level database usage to help you acquire PostgreSQL skills necessary for the AI era from a practical perspective. Based on AI development experience in Silicon Valley, you will learn step-by-step how to design and utilize JSON, indexes, transactions, and even pgvector in real-world services, while mastering methods to solve complex data structures and performance issues.

Let's apply TypeScript to Node.js, add typings to existing npm packages, or create your own TypeScript library.

Through in-depth theoretical explanations of Kafka Connect and detailed practical training that can be used immediately in the field, we will help you grow into an expert in building data linkage and data pipelines based on Kafka Connect that are needed in the field.

This is a course to learn MariaDB, a commercially available database. Even if you are learning about databases for the first time, you can learn it easily.

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.

I learned it the hard way, but I want you to learn it easily. I've discarded unnecessary theories and included only the core essentials of SQL. Build your SQL confidence quickly.

This article introduces the relationship between Nodejs, a server-side JavaScript language, and a database, and explains how to create web applications using Nodejs and a database.

What is Apache Kafka? How does Apache Kafka work? What are the concepts of Apache Kafka? If you are curious, choose this course😎

This course is designed to help students learn and practice PHP programming concepts. It is designed for students who want to learn PHP programming concepts.

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

Understanding Spring Boot + React.js Login (+Social) Service is a course designed to help you deeply understand the authentication flow between frontend and backend, by directly implementing a practical login system that includes JWT-based authentication and social login (Kakao/Google). The frontend is built on React.js, and the backend on Spring Boot, enabling you to learn step by step the practices used in real service environments, such as the Access Token + Refresh Token approach, user state management using HttpOnly Cookie and Redux, Role-based authorization, and social login integration.

This course proceeds in stages where you learn and apply necessary knowledge while building infrastructure, similar to real-world practice.

In this course, you will be able to create a Reddit website from scratch, step by step.

This course teaches you how to implement modern web applications that combine the accessibility of the web with the excellent information management capabilities of a database by linking PHP and MySQL.

IntelliJ IDEA Conf 2025 is an annual online conference hosted by JetBrains that provides valuable sessions for Java and Kotlin developers. It covers various topics including AI adoption, Spring Boot, Gradle, Kafka, database management, and also shares insights on cloud integration, secure coding, developer performance improvement, and advanced development techniques. This conference is open to both professional and beginner developers, offering opportunities to explore the latest technologies along with productivity tips for writing high-quality code faster.

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.