Spring Boot: Practitioner's Guide for Beginners

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.

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.

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 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 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.

Kotlin mastery via virtual payment server course.

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.

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.

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.

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

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.

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

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

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

Spring Web Programming learned while creating a calendar (schedule management)! Completely master Spring with examples you can use right away, not just short snippets~

It doesn't end with just creating one application. We will show you the A-Z of completing a service by connecting a Vue.js modern front-end stack to a backend using Spring Boot.

There are so many benefits to developing Spring Boot with Kotlin. I think it would be good to learn about them through this lecture.

Traditional React development and Next.js development are completely different approaches. This course penetrates the core of the latest Next.js 16 and teaches you the 'real' Next.js way of development. From job portfolio projects to real-world projects, experience how to achieve both performance and efficiency. Let's develop the Next.js way! The course is structured so you can learn by doing, creating actual examples to understand how to apply Next.js features. You'll learn faster through actual code rather than theory, focusing on Server Components and covering Server Actions and caching strategies. Since the goal of the course is to catch up with Next.js's approach as quickly as possible, the lectures are conducted using JavaScript. However, each lecture's examples are additionally provided as course materials created in TypeScript. December 18, 2025 - Updated to Next.js 16

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.

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.

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

I've created an introductory CI/CD course that's easy for non-majors to grasp and immediately applicable in practice!

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.

Learn how to build web APIs and backend logic and integrate them with HTML/CSS/Javascript websites without managing physical servers/network equipment using a free Amazon Cloud account, through a simple Kanban project.

This course is not just simple clone coding or a basic tutorial. By implementing an LMS (Learning Management System) platform like Inflearn from start to finish at an MVP level, it provides an all-in-one solution that freelancers, solo developers, and early-stage startup members can immediately apply in real-world projects. We cover the entire tech stack used in actual production environments at once: Next.js, Flutter, Supabase, Firebase (FCM), AWS, Vercel, Xcode, Android Studio, ElevenLabs, and Toss Payments. You'll experience the complete process of simultaneously developing web and mobile apps, including social login, automatic multilingual dubbing, HLS streaming-based lecture playback, payment integration, and deployment to the App Store and Play Store. This course focuses on the important workflows, configurations, and deployment processes that matter in real-world development, rather than detailed line-by-line coding. Therefore, it's suitable for developers looking to become independent freelancers, teams that need to quickly validate MVPs at startups, and junior developers who want to experience the full scope of real-world development.

Learn Python web development A to Z while making it! Learn everything from web basics to blog development and deployment all at once.

Create a SNS service using Vue and Nuxt frameworks. Learn the full stack knowledge required for the service.

It explains almost everything surrounding the cloud in an easy-to-understand manner. If you listen to it before the actual practice, you will be able to understand development or infrastructure cloud well.

Spring AI + JPA + MySQL Premium Reservation Agent Backend Development with 'Autonomous Behavior' Beyond Chatbots to Agents: The Definitive Guide to Tool Calling and Prompt Engineering

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

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-world work, not just theory, we'll show you a proven way to be recognized as an "AI-savvy developer" at your company.

Experience the power of Type Safe SQL with jOOQ!

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!

Have you ever wondered "how" the many Java libraries and frameworks you use provide this functionality? In this course, learn how to manipulate various codes or objects provided by Java and take your Java skills to the next level.