Spring AI + RAG: Build Production-Grade AI with Your Data -(2026)

This course is designed to help complete beginners overcome the most common challenges in game development: understanding Unity, learning C#, and knowing how to turn ideas into real, playable games. Through years of teaching beginners, I have learned that students struggle most with complex explanations, disconnected theory, and lack of real practice. That’s why this course follows a clear, step-by-step, hands-on approach, where every concept is explained simply and immediately applied in real game projects. Students will build full 2D games from scratch, learning how to create player movement, enemies, levels, UI systems, animations, audio, and complete game flows. By the end of the course, learners will not only understand how 2D games work but will confidently create and export their own games using Unity and C#.

In this course, I guide students step by step through the complete process of creating a detailed cyberpunk-style scene in Blender, starting from Blender’s default cube and ending with a fully rendered, cinematic environment. Throughout the course, I focus on solving the most common problems students face when learning 3D, such as understanding the full modeling workflow, fixing UV issues, adding realistic imperfections, and creating convincing lighting and atmosphere. Every step is recorded in real time, with clear explanations of not only what to do, but why it is done that way. By combining hands-on modeling, texturing, scene building, lighting, and post-processing, this course helps students gain confidence in their Blender workflow and teaches them how to turn a simple idea into a polished, professional-looking scene.

This course is designed to help developers who feel overwhelmed by Docker, Kubernetes, and cloud deployments finally understand and apply DevOps concepts step by step. Based on real-world experience deploying containerized applications to production, I guide students through hands-on labs, clear explanations, and common mistakes beginners face. You will start from the basics of Docker and Kubernetes, build real containers, deploy applications locally, and then move confidently to Azure Kubernetes Service (AKS) with CI/CD pipelines using Azure DevOps. Every concept is explained practically, with a strong focus on “why” and “how”, so you don’t just follow commands—you actually understand what you’re doing and how to use it in real projects.

This course is a complete and structured journey into MySQL, designed to take students from SQL fundamentals to advanced database concepts. Through clear explanations, step-by-step demonstrations, and practical examples, common difficulties such as writing correct queries, understanding joins, or structuring databases are addressed in a simple and progressive way. The course focuses on hands-on learning: each concept is explained, demonstrated, and reinforced with realistic use cases. Students learn not just what to write in SQL, but why it works and how to apply it confidently in real-world database scenarios. By following a logical progression—from basic syntax to advanced features like transactions, views, indexing, and optimization—students gain a deep and practical understanding of MySQL that they can immediately apply in projects or professional environments.

Course Summary: This course teaches you how to create multichannel AI agents that handle customer support across website chatbots, Telegram, emails, forms, and feedback—all without writing a single line of code. Drawing from my experience in helping students and professionals implement real-world AI solutions, I provide step-by-step guidance to design, connect, and deploy AI agents that actually work. You will learn to build a fully functional system, debug common issues, and even monetize your skills for clients or your own business. By the end, you'll have a practical project and ready-to-use AI agent templates.

In this course, I share my real-world experience building production-ready GraphQL APIs using Apollo Server, Node.js, Express, and MongoDB. Over the years, I’ve helped developers move from REST to GraphQL by breaking down complex concepts into clear, practical steps and solving common pain points such as authentication, pagination, performance optimization, and schema design. This course focuses on hands-on learning. You will build a complete GraphQL API from scratch, implement JWT authentication, design scalable schemas, and optimize performance using DataLoader, batching, and caching. Each concept is explained with practical examples so you can confidently apply it in real projects.

This course is a complete bootcamp designed to teach Android application development using Kotlin from scratch. It is structured to guide students step by step, even if they have no prior programming experience. With years of experience in programming and teaching, the instructor focuses on solving the most common problems students face when learning Android development. Each concept is explained clearly through practical examples, hands-on exercises, and real projects. Students will not only learn theory but also understand how to apply it to build real Android applications confidently.

This course is designed to help beginners confidently manage a VPS server and host professional websites without feeling overwhelmed by technical complexity. With over 5 years of experience working with WordPress and VPS-based hosting, I have helped many beginners solve common problems such as slow website performance, poor security, high hosting renewal costs, and limited control on shared hosting platforms. In this course, I break down complex server concepts into simple, step-by-step lessons that anyone can follow. You will learn how to purchase an affordable and high-performance VPS, connect a custom domain, install WordPress or other websites, secure your server, and manage everything using a reliable and user-friendly control panel. I also guide you through setting up Cloudflare for DNS, free SSL, CDN protection, automated backups, FTP access, database management, and a secure email server. By the end of this course, you will have the skills and confidence to manage your own VPS server, host multiple websites, and run a secure, scalable, and cost-effective web hosting environment.

This course is built from real experience teaching beginners who often feel lost when starting Unity and game development. Many students struggle with understanding how scripts work together, how game mechanics are connected, and how to turn simple ideas into a complete playable game. In this course, I guide students step by step, explaining every concept clearly and practically. Instead of overwhelming theory, we focus on building a real 2D space shooter game from scratch. Every script is written and explained line by line so students understand not only what to do, but why it works. The goal is to remove confusion, build confidence, and help students think like game developers. By the end of the course, students are able to understand Unity 2D fundamentals and confidently start their own game projects.

This course is designed for beginners who want to learn Unity 3D through a clear, practical, and problem-solving approach. Based on real teaching experience with beginners, this course focuses on explaining concepts step by step, in simple language, without assuming any prior knowledge. Common beginner problems—such as understanding GameObjects, movement, shooting logic, enemy behavior, and UI—are addressed carefully with hands-on examples and clear explanations. Instead of overwhelming students with theory, each lesson builds directly on the previous one, helping learners understand why things work, not just how to copy code. By following the full project from start to finish, students gain confidence and a strong foundation in Unity 3D by creating a complete and playable Space Invaders–style 3D game.

This course is designed to help learners master AI prompt engineering and confidently use ChatGPT and generative AI tools to solve real-world problems. Through my experience working with students, professionals, and entrepreneurs, I have identified a common challenge: many people use AI tools without knowing how to instruct them effectively. This often leads to inaccurate, generic, or unusable outputs. In this course, I guide learners step by step on how to communicate with AI the right way, using proven prompt patterns and practical examples. By combining clear explanations, real-life use cases, and hands-on techniques, I help students transform AI into a powerful assistant for writing, business growth, productivity, presentations, meetings, and creative work. This course focuses on practical results, not theory, so learners can immediately apply what they learn to their personal or professional projects.

This course is designed to help students move beyond theory and actually build real AI-powered marketing automation systems. Drawing from hands-on experience designing and implementing AI workflows, I focus on solving common problems students face—such as disconnected tools, repetitive manual tasks, inconsistent content creation, and lack of scalable automation. Rather than relying on abstract explanations, I teach through practical demonstrations and step-by-step workflows using n8n as the central automation platform. Students learn by building real marketing automations, AI agents, and multi-step workflows that connect ChatGPT, APIs, and business tools into reliable systems. By the end of the course, students don’t just understand AI automation—they know how to design, deploy, and orchestrate agentic AI workflows that solve real marketing problems efficiently.

This course provides a complete, concise, and practical introduction to Jira and Confluence for Agile project management. Based on real-world experience, I guide students step by step through setting up Agile projects exactly as Jira and Confluence were intended to be used. Throughout the course, I focus on solving the most common challenges beginners face: understanding Agile concepts, organizing backlogs, planning sprints, managing teams, and documenting work effectively. Instead of theory overload, I demonstrate clear workflows, real examples, and best practices that students can immediately apply in their own teams or organizations. By the end of the course, students gain the confidence to manage Agile projects, collaborate efficiently, and use Jira and Confluence as professional project management tools.

This course is built from real-world agile delivery challenges faced by Scrum Masters, Project Managers, and Product Managers who struggle with time pressure, unclear requirements, overloaded backlogs, and inefficient meetings. Through hands-on demonstrations and step-by-step workflows, I show students exactly how to use Generative AI tools—such as ChatGPT, Jira AI, Confluence AI, Rovo AI, and Fireflies.ai—to solve these everyday problems. Instead of theory, the course focuses on practical use cases: creating product goals, refining user stories, generating acceptance criteria, planning sprints, automating documentation, and improving team collaboration. Each lesson is designed to help learners apply AI immediately in their daily work, build confidence with industry-standard tools, and develop AI-powered habits that increase productivity, clarity, and leadership effectiveness in agile environments.

This course is based on a real production workflow behind a Breaking Bad–inspired cinematic animation created and published on my YouTube channel. Instead of showing only final results, I focus on explaining every step of the process in detail, including the decisions, techniques, and problem-solving methods used during production. Many students struggle to understand how all parts of a cinematic scene fit together — environment creation, animation, lighting, assets, and final assembly. This class is designed to solve exactly that. Through a 4-hour in-depth tutorial, I guide you step by step through the creation of two full scenes, sharing practical techniques, common mistakes to avoid, and a clear production workflow you can reuse in your own projects.

This course is designed to help students confidently create large-scale landscape scenes in Blender without feeling overwhelmed by complex workflows. Throughout the class, I guide students step by step, explaining not only what to do, but why each decision is made. Common beginner problems—such as scene scale, camera placement, managing large environments, and shader complexity—are addressed clearly and practically. By breaking the entire process into manageable stages, students can follow along easily while still learning professional techniques used in real environment production. The course starts with Blender basics and gradually introduces more advanced concepts like volumetrics, shader mixing, photogrammetry assets, lighting, and compositing. My teaching approach focuses on clarity, real-world dimensions, and efficient workflows, ensuring students can recreate the process on their own and apply it to future projects.

In this course, I guide students step by step through the process of creating a procedural city generator in Blender using Geometry Nodes, and using it to build a cinematic Batman-inspired scene. The course is designed to solve one of the most common problems beginners face: understanding Geometry Nodes and knowing how to apply them in real projects. Instead of focusing on theory alone, I teach through a practical, beginner-friendly workflow, explaining every step and decision in a clear and efficient way. Students will learn how to model optimized buildings, create flexible Geometry Nodes setups, control lighting through shaders, and finally compose and render a complete cinematic scene. My goal is to help students not only follow along, but truly understand how to reuse these techniques in their own future projects.

This course is designed to guide beginners through a complete cinematic workflow in Blender, from the first idea to the final rendered scene. Drawing from practical production techniques, the course focuses on solving common beginner problems such as inefficient modeling, overcomplicating textures, and struggling to achieve realistic results with limited time. Each step is explained clearly and recorded in real time, showing not only what to do, but why it works. Students will learn how to create a visually rich cinematic scene using smart low-poly modeling, collage textures, efficient UV unwrapping, and emissive shaders. The course also covers lighting, environment creation, volumetrics, and scene composition to achieve a moody, cinematic look. By following a structured, step-by-step approach, students gain confidence in Blender while learning time-saving techniques they can reuse in future projects. Only Blender is required, making this course accessible and easy to follow for beginners.

In this course, you will learn a complete CG and VFX workflow inside Blender by creating a cinematic Batman-inspired scene from start to finish. We begin by analyzing real movie footage from The Batman (2022) to build strong visual references for lighting, camera placement, and color grading. Step by step, you will learn how to block a scene, project camera footage, match CG with live-action, and smoothly blend both elements to achieve a cinematic result. Around 90% of the final scene is created in CGI, making this course ideal for learning how professionals combine live footage and CG efficiently. The course focuses on practical techniques, helping you avoid common beginner mistakes in lighting, camera matching, and post-processing. By the end of the course, you will have a complete cinematic shot and a solid foundation in Blender-based CG and VFX workflows that can be reused in your own projects.

If you are a student or developer who is using or studying the Java programming language, you will learn various methods of testing your applications that you must know.

In a world where all resumes look the same, 'differentiation' makes the difference in getting hired. Over 6 weeks, learn 4 practical resume strategies directly from a backend professional.

Is your Java persistence application a well-built, high-performance enterprise application, or slow code that just barely runs? The difference between the two is just a fine line. Let's study JPA and Hibernate properly and build high-performance applications!

If you have just finished the Java Basics book or are a Java beginner, I expect that through this course you will learn design patterns and be able to program with more efficient code when programming using Java.

"The Era of Coding with AI: A New Productivity Paradigm for Java Developers" This course is a practical Cursor AI utilization guide for Java developers. Beyond simply copying AI-generated code, you'll learn Vibe Coding methods that maximize development efficiency through collaboration with AI. By leveraging Cursor's powerful code understanding, refactoring, and documentation features, you'll master AI coding workflows step by step that can be immediately applied to real-world projects. In an era where AI writes code for us, "developers who can effectively work with AI" now have the competitive edge. Start your upgraded development experience as a Java developer with this course.

Let's create a dashboard by visualizing various data.

OpenAI Practical Application Course, where you directly implement various AI functions such as text, image, voice, translation, and content review in a Java environment.

Learn how to analyze 5 million Korean apartment transaction data using PostgreSQL. Covers the process of data cleaning, transformation, and deriving meaningful insights through various SQL queries.

Stop copy-pasting code! 🙅‍♂️ This is a "real" conceptual lecture that dives deep into everything from how agents work to their architecture and design philosophy. Beyond just learning how to build them, I will help you develop an eye for designing entire systems. Build a solid foundation here that remains unshakable amidst the technology trends of 2026! 🧠✨

When you're doing backend development, at some point you face this dilemma. As services grow and traffic increases, there comes a moment when simple REST communication and CRUD structures feel limiting. I experienced the same problem in real-world work and went through many trials and errors between performance and structural complexity. The solution I chose in that process was NATS. Its simple configuration based on a single binary, ultra-low latency performance in microseconds, and the fact that it provides just the right amount of essential features for real work—from Pub/Sub to Queue Groups and JetStream—made it a very practical choice in actual service environments. This course is not about listing NATS features. Based on the problems I faced in real work, I explain with code and flow diagrams which situations led me to choose NATS, why, and how I designed the architecture. This is a course designed to help everyone—from those new to messaging systems, to backend developers preparing for jobs, to senior developers contemplating better architectures—understand distributed systems and grow to the next level.

Legacy Java Code, The Most Practical Way to Fix It "Without Breaking" The reason refactoring is scary isn't because you don't understand the principles, but because you don't know how far you can trust your IDE. In this course, 👉 Using *only the refactorings guaranteed by IntelliJ IDEA* 👉 You'll develop **the sense to improve production code quickly and safely**.

I have created an 'Introduction to Elasticsearch' course that is easy for non-majors to understand and can be applied immediately in practice!

💡 Even non-developers can go from startup MVP to monetized service in just 10 hours with AI! 💰 Development that used to cost tens of millions in outsourcing fees now completely solved for 120,000 won 🎯 Complete 5 real business projects including business card recognition, sentiment analysis, and location analysis 🔥 If you're a planner, marketer, or aspiring entrepreneur, implement ideas without developers ⚡ Start now and acquire lifelong development independence skills!

Learn the easiest way to handle AI with Spring AI. Let's learn Spring AI by building a RAG chatbot.

The era of 'your own platform CEO' begins, even for IT beginners, with just an idea, using AI and GNUBOARD! We'll demonstrate the full development process from planning to deployment, and share diverse monetization methods like ads and shopping malls. Start your online business now!

I'll show you how Java backend developers using IntelliJ can maximize productivity with Claude Code. In particular, I'll help you completely solve the Vibe coding environment issues that Windows users experience.

Java is not difficult to learn. It's just that it becomes difficult because you learn too many unnecessary things. There are things in technology that can only be understood when you reach that stage. But, it's just hard because you try to cram too much unnecessary stuff into your head. Technology is experience. Let's learn quickly and simply!!

If you have started Java development but feel overwhelmed when trying to solve a problem, it is time to study design patterns. I will explain 10 of the GoF design patterns that I personally use the most.

Knowing design patterns will make it easier to learn not only Spring but also many other technologies and programming languages. It will also help you develop more flexible and reusable object-oriented software.

This course is a video lecture that systematically covers the core modern JavaScript syntax essential for learning React.js and Vue.js frontend development. It is structured to help you develop efficient coding skills through ES6+ syntax, latest features, and practical examples that can be directly applied to work and learning.