Building a Chat Platform Using Spring Boot

Learn SAGA transaction management techniques for maintaining data consistency in distributed environments through hands-on practice. Configure 3 microservices using Spring Boot and Docker, and implement both Orchestration and Choreography patterns with Kafka and MySQL. Through this course, you can master core concepts that are immediately applicable in practice, including distributed transaction operation principles, compensating transaction design, and failure recovery handling.

This course covers RPC communication techniques that maximize performance in large-scale MSA (Microservice Architecture) environments. Going beyond simple gRPC practice, you'll learn how to implement stable and efficient inter-service communication in real production environments where hundreds of microservices operate simultaneously. Based on Golang, the course covers Protocol Buffers (proto) syntax writing, automatic code generation and service implementation, gRPC structure and advantages over existing RPC, and performance optimization strategies with a practical focus. To ensure easy understanding for non-majors and server development beginners, the course provides step-by-step explanations from RPC concepts to gRPC's internal operating principles, enabling you to develop practical skills that can be immediately applied to real services.

Learn how to design and process large-scale data architecture that handles hundreds of billions of data records using only pure SQL and MySQL's core features, together with a Toss developer who handles hundreds of billions of financial traffic transactions and a developer who started as a non-major and is now developing platforms in Pangyo.

Kotlin mastery via virtual payment server course.

How to Handle Explosive Traffic Growth? Learn to build resilient and flexibly scalable architectures through practical design patterns based on EDA (Event-Driven Architecture) using Kafka, Spring, CDC, and Temporal. Explained clearly and simply with real-world experience from Kakao developers, making it understandable even for non-majors. A hands-on focused course covering real-time data flow, event processing, and microservice integration all at once!

This covers effective Redis usage, including precautions and applications, illustrated with examples from real-world practice or renowned historical cases.

This course covers how to set up multi-module projects from scratch using Kotlin and Spring Boot. It proceeds with a hands-on approach, covering everything from the basic concepts of modularization to Gradle configuration, managing dependencies between modules, and actual application development. If you are a beginner or intermediate developer looking to learn the fundamentals and practical application of multi-modules, please refer to this course.

In this course, rather than covering the theory directly, you will learn how to use Redis effectively in your code through hands-on practice.

We will develop a scalable order processing system capable of real-time event streaming using Spring Boot 3.x + Kotlin to build a Kafka cluster, leveraging PostgreSQL CDC with Debezium Connect and Apache Avro schema.

Learn the essential process of building Observability in a microservices architecture (MSA) environment from basics to practical implementation. Through step-by-step hands-on practice, you'll master standardized data collection using OpenTelemetry, trace storage and search with Grafana Tempo, and visualization using TraceQL. You can learn the process of tracking service flows through distributed tracing, identifying bottlenecks, and analyzing the root causes of failures.

Let's build a project using Ktor, the most popular project in Kotlin, and master Kotlin! 😆

Using Spring Boot 3.x + Kotlin, we build a 3-instance cluster, and utilizing Redis Pub/Sub distributed messaging and an Nginx load balancer, develop a scalable WebSocket real-time chat server capable of handling large-scale traffic.

This course is a master class that teaches Kotlin's 🌺 Coroutine, covering everything from theoretical foundations to practical application in a standard manner. It systematically covers core principles and structure, the necessity of asynchronous programming, Coroutine builders and scopes, exception handling, channels, Flow, and other key features frequently used in practice, step by step. Each concept is explained with hands-on examples, making it easy for beginners to understand and immediately apply them. This is the best introductory and practical course for developers who want to build strong Coroutine skills for real-world use.

Learn the process of building data pipelines using Apache Airflow from basics to practical application. Understand Airflow's core concepts and architecture, and master advanced design patterns frequently used in practice such as dynamic DAGs, parallel processing, distributed processing, and Custom Operators through hands-on exercises. Set up a practice environment with Python and Docker, and develop practical skills to design and operate real workflows.

You can learn how to send emails using AWS and Spring. Through this, you can study how to create an email verification system.

This course is a master class that systematically covers the fundamental principles and practical applications of MongoDB. Starting with core MongoDB concepts, you will systematically learn essential topics for practical work, such as database design, CRUD operations, indexing, aggregation pipelines, performance optimization, transactions, and security. It explains topics step-by-step so even beginners can understand, and you can deeply learn the working principles of MongoDB through exercises and examples. This is the best introductory and practical course for developers who want to build strong MongoDB skills for practical work.

I am covering the know-how on how I studied and got a job, starting as a non-major.

We develop a chat service using web socket/stomp and springboot. We also configure a simple screen using vue.js, which is a relatively easy framework. We also configure multi-server scalability design using redis pub/sub.

I've created a beginner-friendly and practical 'Introduction to Elasticsearch' course!

You can quickly and easily learn the basics of authentication and authorization through tutorials using Spring Boot, Spring Security, and JWT.

If you are already a developer or want to become a developer but did not major in computer science and are weak in databases, gain lifelong knowledge with this one course!

Claude + IntelliJ TodoList Development - Complete MCP Mastery Learn how MCP works perfectly by creating a TodoList with Claude and IntelliJ.

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

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.

I'll show you how Java backend developers using IntelliJ can maximize productivity with Claude Code. I'll especially help those using Windows environments completely solve vibe coding environment issues.

You will learn how to set up/use spring boot actuator and how to create your own custom endpoints and metrics. You will learn not only how to use it, but also the internal code and basic knowledge of spring boot, so you can understand it a little more deeply.

A Java advanced project course for beginner developers who want to develop practical skills! We'll build a console-based kiosk ordering system together using Spring Core, JdbcClient, and H2 DB.

A practical course on easily building a super simple bulletin board with Spring Boot and React.js! This course focuses less on theory and more on hands-on practice, covering the web application development process for quick completion.

This is a full-stack hands-on course where you'll clone ChatGPT and implement everything from scratch. From Spring Boot server to React frontend! This isn't just a course where you follow along with code, but one that guides you to build a high-quality AI chatbot service through actual service deployment.

AI is no longer a choice but a matter of survival. Reduce development time from 3 days to 30 minutes, delegate repetitive tasks to AI, and focus on solving more important problems. With AI-native development methods that you can apply immediately in real work rather than just theory, we'll show you the definitive way to be recognized as "the developer who's good with AI" at your company.

Handling media (video, audio) on the web is now easier than ever! Learn the MediaStream API and WebRTC by following along step by step.

This course proceeds in stages, similar to the actual work, by learning and applying the necessary knowledge while configuring the infrastructure.

Learn the deployment process in the following order: Manually deploy Spring Boot with Chicken Combo value -> Deploy with Docker -> Github Action CI/CD.

Learn Springboot + Flutter RestAPI Board Creation Faster Than Anyone Develop a CRUD server with Springboot and create your own board with Flutter!

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.

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

Build a Springboot + iOS RestAPI Bulletin Board: Learn Faster than Anyone Develop a CRUD server with Springboot and create your own bulletin board with iOS!