Ultra-Low Latency Messaging and Distributed Systems with NATS by a Naver Developer

This course explores microservice architecture and distributed environments not as a simple list of technologies, but from a 'design perspective' required in actual work and interviews. Starting from the differences between monolithic and MSA, it progressively covers incremental migration strategies, modular monoliths, clean architecture and hexagonal architecture, clearly explaining why each choice is necessary and the trade-offs involved. Through hands-on practice, you can directly verify the intent of the structure and learn about core issues inevitably encountered in distributed environments—such as data consistency, transactions, inter-service communication, and failure handling—through realistic scenarios. Based on actual questions and perspectives from Kakao interviewers, this course aims to go beyond simple knowledge acquisition and elevate your way of thinking about distributed systems to the next level.

Most developers still remain stuck with Batch and CronJob when talking about data processing. However, in real service environments, data is constantly being generated, and if you can't process that flow immediately, it leads to delays, bottlenecks, and consistency issues. I too have directly experienced real-time recommendation, state synchronization, and event delay problems in high-traffic environments, and have countless times wondered, "Is it right to handle this with batch processing?" This course starts from exactly that question. Using Apache Flink, it explains from a practical perspective how to compute data the moment it flows, safely manage state, and produce accurate results based on Event Time. Rather than simple theoretical explanations, you can experience how real-time stream processing systems are designed and operated through actual source code and architecture. For those who found real-time processing vague, or were curious about the world beyond messaging, this course will provide clear direction.

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!

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.

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.

Learn SAGA transaction management techniques for maintaining data consistency in distributed environments through hands-on practice. Configure three 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 real-world scenarios, including distributed transaction operation principles, compensating transaction design, and failure recovery handling.

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.

Kotlin mastery via virtual payment server course.

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

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.

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

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.

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.

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

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.

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

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.

You can learn about JWT and ws communication using Spring Boot, and how to handle high TPS.

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

We will learn how to create a system to support large amounts of data and traffic by creating it directly with Spring Boot.

Learn SAGA transaction management techniques for maintaining data consistency in distributed environments through hands-on practice. Configure three 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 real-world scenarios, including distributed transaction operation principles, compensating transaction design, and failure recovery handling.

From Docker, Kubernetes to microservices, CI/CD, and service mesh, you can easily learn not only the basic theory but also the actual application implementation through examples. By organizing only the core contents necessary for actual use, it provides a starting point for learning about the element technologies covered in the lecture.

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.

[Newbies to Web Development Only] Let's Build a Spring Boot REST API Step-by-Step, the Easy Way

This course is a learning process that involves studying the fundamental theories of data structures by directly implementing them through JAVA programming. Rather than simply learning theory, it is structured to enable a deeper understanding of data structure principles by implementing them with actual code. Learners will theoretically learn core data structure concepts such as arrays, stacks, queues, lists, trees, and graphs, while simultaneously implementing them in JAVA code to experience their actual operation processes. Through this approach, rather than rote memorization, learners can develop logical thinking skills and problem-solving abilities, enjoying the synergistic effect of learning programming and data structures together. 👉 Upon completing this course, learners will master the basic concepts and structural characteristics of data structures, as well as the ability to implement and apply them in actual development environments, establishing a foundation for designing more efficient and robust programs.

Based on an understanding of Reflection and Annotations, it helps you clearly understand how the Spring framework operates!

It covers major updates from Java 9 to Java 21 in detail. It will be continuously updated as newer versions are released up to Java 31.

"Becoming a Developer Who Excels at React" has been published. This book provides a solid foundation by systematically guiding you from the basic principles of the web needed before learning React to the latest React hooks. Through over 40 diverse hands-on projects and abundant practical examples, you can apply theory directly to real-world situations and develop problem-solving skills. Additionally, it helps you grow into a developer capable of building high-quality React applications by learning essential modern web development technologies such as Redux Toolkit, Zustand, and Firebase.

Learn the overall process of developing and deploying a website through generative AI (Chat GPT, Cursor AI).

How to Use Storybooks A to Z. We show you everything about storybooks.

You can quickly experience the process of deploying a sample e-commerce service to AWS and continuously improving it into a robust and efficient environment.

From concepts to unique projects, master JavaScript and React all at once with this course. Short learning, long application - a 17-hour All-in-one course!

We will apply it in practice by crawling sites such as Naver, Amazon, Twitter, YouTube, Facebook, Instagram, and unsplash.com.

This is a full-stack restaurant map tutorial that allows you to learn everything from front-end, back-end, Kakao Map API usage, and deployment all at once while creating a restaurant map of your favorite YouTuber.

Learning by Doing: 정보처리산업기사 I have prepared everything for passing the 정보처리산업기사 course-evaluation practical exam.

Experience the power of Type Safe SQL with jOOQ!

A portfolio-focused course on directly deploying React frontend and SpringBoot backend to AWS cloud! This course is helpful for those who want to quickly deploy frontend and backend projects to their portfolio! You'll be able to practice step-by-step in a short period the knowledge needed for deployment, from server setup to Docker, Domain connection, Nginx, and HTTPS implementation!

Did you give up while studying Spring? Even complete beginners new to coding and non-majors can make it from JSP to Spring Boot without giving up - we'll open the path to Spring Boot for you.

This is a Java course for those who are new to programming. You can easily learn Java by following along with the code.