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

No coding skills? No problem! Turn your ideas into real profit in just 4 weeks. Use AI and the latest tools to build a website and an app simultaneously and launch your service right away.

With step-by-step explanations that even beginners can easily understand, the once-vague coding tests will become clear. Learn only what you need and apply it to real-world practice right away!

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.

We live in an era where AI can generate 10 files at once. However, if you can't track where the code changed, if it conflicts with your teammates' work, or if you don't know how to revert it—your productivity will suffer no matter how well you use AI. This course isn't just a list of commands like git add and git commit. It provides a visual understanding of the principles behind safely managing AI-generated code and merging it with your team's work. In just two hours, you will transform into a developer who can freely track, revert, and merge any code, whether it was created by AI or written by yourself.

In a world where every resume looks the same, "differentiation" is what gets you hired. Over the course of 6 weeks, learn 4 practical resume strategies delivered directly by an active backend professional.

AI is no longer a choice, but a matter of survival. Shorten development tasks that used to take 3 days down to 30 minutes; leave repetitive tasks to AI and focus on solving more important problems. Through AI-native development methods that are practical rather than theoretical, we will show you the definitive way to be recognized as an "AI-savvy developer" at your company.

You've probably written SQL using JdbcTemplate before, right? Everyone has likely had that experience of sighing while having to fix both the SQL and the RowMapper every time a single column changes. This course starts from that very pain. Doing a single SELECT with pure JDBC takes 35 lines. You open a Connection, create a PreparedStatement, iterate through the ResultSet, and if you miss a single close(), the server crashes. After typing through this hell yourself, when you finally encounter a single line of JPA's save(), you'll feel "this is why we use JPA" not just in your head, but in your hands.

Beyond simply copy-pasting with AI, you will learn how to actually automate repetitive tasks for non-developer professionals by connecting Claude Chat, Cowork, MCP, n8n, Supabase, and Vercel. Set against the backdrop of a virtual company called DingcoLabs, you will follow hands-on scenarios for PM, Marketing, Sales, CS, and HR to build work automation systems that can be applied to your company immediately.

This is an introductory backend development course where you learn through understanding rather than memorization, and experience rather than theory. Instead of reciting a Googled definition when asked "What is JPA?" in an interview, this course will empower you to give an answer based on experience, starting with "Well, I've been through JdbcTemplate hell..." You will gain a deep, intuitive understanding of "why we use frameworks" by experiencing firsthand how 30 lines of pure Java ServerSocket code shrink down to just 7 lines in Spring Boot. After 6 sessions, you will walk away with a functional portfolio piece: a Todo List REST API built with Spring Boot + JPA.

If you ask an AI to "get the top 10 sales," it will whip up a plausible-looking query in no time. However, to determine if that query is actually correct, if the results of joining three tables are accurate, or if it's performing a full scan on 500,000 records without an index—you ultimately need a foundation in DB basics. This course doesn't cover anything overly difficult. In just 2 hours, you will learn the entire flow of SQL by coding along, covering exactly what you need to know before giving instructions to an AI. By the end of this lecture, you will no longer feel uneasy when faced with a query generated by AI.

You've probably written SQL using JdbcTemplate before, right? Everyone has likely had that experience of sighing while having to fix both the SQL and the RowMapper every time a single column changes. This course starts from that very pain. Doing a single SELECT with pure JDBC takes 35 lines. You open a Connection, create a PreparedStatement, iterate through the ResultSet, and if you miss a single close(), the server crashes. After typing through this hell yourself, when you finally encounter a single line of JPA's save(), you'll feel "this is why we use JPA" not just in your head, but in your hands.

A course that helps you understand core database concepts and trains you to explain them verbally in interviews.

This course explains everything from the basics of MySQL to its practical application in a step-by-step manner, making it easy to understand even for those learning databases for the first time. Rather than just providing simple theoretical explanations, the course focuses on real-world problem scenarios and teaches you how to write SQL and handle data through hands-on practice. The curriculum is systematically structured to cover the entire process, from DBMS concepts to MySQL installation, basic SQL syntax, data manipulation, and the use of functions. In particular, the goal is to help you understand "why it is written this way" through repetitive practice and to develop the ability to write queries on your own.

This course is a step-by-step course that allows you to learn and understand what the WEB MVC framework is and how the WEB MVC framework has been transformed into the Spring WEB MVC framework through the TPC (Think-Express-Code) technique.

This is the second lecture following the Database Design Fundamentals course. This is a practical course that focuses on real-world projects from start to finish. After understanding all the lecture content, you will be able to freely design databases.

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.

Extract and utilize data through Oracle 18c and become a database expert!

A course where you understand the core concepts of Java and Object-Oriented Programming (OOP), and even train to explain them verbally in interviews.

Channel Talk interviewers will directly analyze the difference between failing and passing answers to the same questions, and help you prepare for actual follow-up questions.

Channel Talk interviewers will directly analyze the difference between failing and passing answers to the same question and help you prepare for actual follow-up questions.

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

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

I learned it the hard way, but I want you to learn it easily. I've discarded unnecessary theories and included only the core essentials of SQL. Build your SQL confidence quickly.

This course goes beyond simple CRUD-level database usage to help you acquire PostgreSQL skills necessary for the AI era from a practical perspective. Based on AI development experience in Silicon Valley, you will learn step-by-step how to design and utilize JSON, indexes, transactions, and even pgvector in real-world services, while mastering methods to solve complex data structures and performance issues.

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.

Learn practical core Java object-oriented concepts easily via example code.

Based on questions from major game companies such as Nexon, NCSOFT, Krafton, and Netmarble, this explains core C++ concepts and problem-solving skills that job seekers and career changers must know. Pass job tests and technical interviews all at once with actual exam questions from the past 10 years.

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.

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.

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