Backend Interview Essential Crash Course to Complete in 3 Days [NAVER-Kakao-LINE-Coupang-Baemin-Danggeun-Toss]

With step-by-step explanations that even beginners can easily understand, coding tests that seemed vague become clear. Learn only what you need and apply it directly to practice!

No coding knowledge needed! Turn your idea into real revenue in just 4 weeks. Using AI and the latest tools, create both a website and app simultaneously and connect them directly to services.

AI is no longer a choice, but a matter of survival. Reduce development that took 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, not just theory, we'll show you the definitive way to be recognized as a "developer who's good at AI" at your company.

This is a backend development introductory course where you learn through understanding rather than memorization, and experience rather than theory. Instead of answering the interview question "What is JPA?" by reciting a Googled definition, this course enables you to give an experience-based answer that starts with "I've been through JdbcTemplate hell..." You'll directly experience the process of reducing pure Java ServerSocket from 30 lines to Spring Boot's 7 lines, and understand with your whole body "why we use frameworks." After 6 sessions, you'll have in your hands a working portfolio: a Todo List REST API implemented with Spring Boot + JPA.

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.

"I know I need to study SQL, but I don't know where to start." When you open a database book, terms like normalization, B-Tree, and clusters... it's daunting right from the start. This course strips away all those complex theories and includes only what you truly need. Where are KakaoTalk messages stored? Why is the MapleStory trade window secure? Starting with everyday examples like these, you can grasp the entire flow of SQL in just 2 hours by coding along through installation → creating tables → CRUD → JOIN → and indexes.

I'm going to teach you the core concepts of Python in 60 minutes! I'm not focusing on blind grammar, but on why and when to use it.

Make the most of relational database systems!

This is a practical backend course designed to cultivate the service planning and design thinking skills that developers need in the AI era.

[TPC DB!] A course that allows you to learn database modeling while thinking, learn database modeling step by step, and master everything from database modeling to web programming implementation all at once.

I've created a 'MySQL Performance Optimization Beginner/Practical Course (SQL Tuning Edition)' that's easy to understand even for non-majors and can be immediately applied in real-world situations!

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

Based on problems from major game companies like Nexon, NC, Krafton, and Netmarble, this explains essential C++ concepts and problem-solving skills that job seekers and career changers must know. Pass technical tests and interviews in one go with 10 years of actual exam questions.

This course teaches MS-SQL through baseball/company databases.

I will transform the Engineer Information Processing written exam (Subjects 1–5) from a "test you solve by memorizing" into a "test where you connect clarified points directly to your score." This is an ultra-compressed lecture designed to help you grasp the entire flow within 3 days. It extracts only the core concepts repeated in past exams, structured to be understood even if viewed right before the test. The course is designed for short-term success by clearly distinguishing between frequently confusing concepts, trap points in multiple-choice options, and what needs to be memorized versus what only needs to be understood. "I'm short on time, but the scope is too broad." "I feel like I know the material when reading the book, but I keep getting the questions wrong." This lecture is for students facing these exact challenges.

This is a course on creating a practical Unity game with a database. You can learn through lectures about aspects that are difficult to encounter.

This course is a practical program where you will master Kotlin-based AI agent development by building your own coding agents. Using Koog, an AI framework built with Kotlin, you will learn step-by-step how to implement coding agents similar to Claude Code, Cursor, and Junie. Koog is more than just a simple server-side framework; it integrates seamlessly with Spring and offers the scalability to connect with various environments—including Android, iOS, Desktop, and Web—through Kotlin Multiplatform (KMP). By building intelligent agents that can read, analyze, modify, and generate code, you will gain hands-on experience in AI agent architecture, strategy, context handling, and tool integration.

This is a lecture using the only domestic e-government framework and Layered Architecture, which are widely used in practice but not available in Korea. In this lecture, we will learn how to build the backend and server side of web development using the Spring Framework and the e-government standard framework.

Through this lecture, you can learn about the characteristics and background of the Kotlin language, grammar and operation principles, usage examples, and things to be careful of when using Java and Kotlin together.

A course that helps you understand core Java and Object-Oriented Programming (OOP) concepts, and includes practice explaining them verbally in interviews

This lecture comprehensively organizes the content that would be good for those who want to get a job as a new Spring Java backend developer, especially those who are about to have an interview.

Learn common components of global-scale services through popular papers, books, and articles.

A beginner's guide to SQL coding! We'll teach you the secrets of writing, interpreting, and validating SQL.

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.

It covers just two things properly: object-oriented programming and the JVM! Plus, it throws in linked-list-based linear data structures.

SQL data analysis! We will teach you how to solve practical problems that are applicable in the field, quickly and easily!

By implementing various practical data analysis cases using SQL, you can simultaneously improve your data analysis and SQL utilization skills.