CS Interview Preparation Guide: Java Edition – Directly from Channel Talk Interviewers

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.

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 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.

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.

Learn the SAGA transaction management technique for maintaining data consistency in distributed environments through a hands-on approach. You will configure three microservices using Spring Boot and Docker, and implement both Orchestration and Choreography patterns using Kafka and MySQL. Through this course, you will master core concepts applicable to real-world scenarios, including the operational principles of distributed transactions, designing compensating transactions, and handling fault recovery.

Through this course, you will gain a deep understanding of clean code principles and be able to write clean code based on object-oriented thinking. This course is for anyone curious about clean code and object-orientation, and everyone who truly wants to write good code.

This course goes beyond explaining the concepts of Spring Batch and covers how to actually integrate Spring Batch into a service that is already running. Based on structures used in real-world practice, you will learn by directly implementing everything from Batch Job configuration and execution flow to data processing structures. Rather than simple examples, it provides step-by-step explanations based on professional architectures, covering Batch Job configuration, execution flow, and data processing structures. In particular, we focus on: How to connect Batch to an existing Spring Boot service and how to build a structure that can be operated stably. Through this course, you will: ✔ Be able to build Batch directly into existing services ✔ Be able to design large-scale data processing structures ✔ Reach a level where you can apply these skills immediately in the field 👉 This is not a "theory lecture" 👉 This is a practical course on integrating it into actual services

This course is for developers who want to find fundamental solutions in environments where response times slow down as traffic increases, thread pools are quickly exhausted, and bottlenecks worsen with more external API calls. It helps you look at problems from the perspective of changing the architecture itself, rather than simply scaling out servers. Through this course, you will first understand the limitations of the traditional Spring MVC "Thread per Request" model. You will examine at the code level why throughput doesn't increase even when CPU resources are available, and exactly how blocking I/O occupies system resources. Next, you will learn the concepts and standard specifications of Reactive Streams and master how to handle data streams using Reactor's Mono and Flux. Beyond simple usage, you will learn through hands-on practice how data flows start, how they are consumed, and how throughput is controlled. In particular, you will directly implement design patterns that prevent OOM (Out of Memory) or overloads using Back Pressure. Additionally, you will understand the event loop-based processing structure of Spring WebFlux and conduct comparative exercises on how Non-Blocking I/O operates during actual request processing. By placing MVC and WebFlux side-by-side to verify their structural differences, you will also establish criteria for when to choose Reactive. This goes beyond simply "learning asynchrony." You will learn how to handle more requests with fewer threads, how to maintain a stable flow in environments with high external API dependencies, and develop the design intuition to secure throughput in high-concurrency environments.

This course was created based on my personal experience passing the very first revised Information Processing Engineer practical exam, which had a pass rate of only 5.34%. The Information Processing Engineer practical exam can no longer be prepared for through simple memorization alone. In particular, the ability to read the execution flow of C, Java, Python, and SQL code to track results, as well as the ability to accurately distinguish short-answer concepts and write them as answers, has become crucial. This course is structured to help even beginners who are new to programming follow along step-by-step, covering everything from creating variable tables to tracking C, Java, Python, and SQL code, core practical terminology, and written exam subjects 1 through 5. Rather than being a video-centered course, this is a text-based course designed for fast reading and repeated review. It makes it easy to look up necessary parts again and focuses on practicing how to derive answers at the testing center by following the code and explanations directly. The 1st update covers the practical programming sections: C, Java, Python, and SQL. The 2nd update will organize core terms and concepts required for the short-answer practical questions and provide a "Stepper Simulator" to practice code tracking directly. The 3rd update will sequentially expand to cover written exam subjects 1 through 5. The Stepper Simulator is designed so that you don't just stop at reading explanations; you can understand how variable values change as the code executes line by line by following along yourself. If you have any questions while taking the course, please leave them in the Q&A. I will respond as quickly as possible to ensure your learning doesn't get stuck.

Through the 25 patterns of OODP, you will learn various ways to design software in an object-oriented manner.

Even people who are studying Java for the first time can easily understand it. You'll learn Java through theory with rich explanations and hands-on practice.

Learn about the uses, pros and cons of various design patterns while creating a drawing board with TypeScript/JavaScript. Learning the canvas API is a bonus!

Learn various design principles needed to write object-oriented code, focusing on working code.

We'll teach you the true essence of object-oriented programming. Knowing terms and syntax like class, object, self, super(), and interface doesn't mean you understand object-oriented programming. Object-oriented programming is not simply a collection of syntax, but rather a philosophy on how to solve the problems of increasingly complex software. You can only use it properly when you understand the history and philosophy behind it. In this course, we first explain what problems object-oriented programming was created to solve, and what kind of thinking and design philosophy it embodies, independent of any specific language. Then, using Python as a tool, we gradually cover through hands-on practice how object-oriented concepts are designed and implemented in actual code. Through this course, you'll gain not object-oriented programming that merely follows syntax, but object-oriented programming that you can think through and design, and object-oriented thinking skills that remain solid even when the language changes.

Regardless of the field! This is a lecture that covers the core fundamentals that developers must know in practice in an easy + code-oriented way. I highly recommend this lecture to all junior developers and job seekers who want to grow.

It's time to master Java's various features so you can apply them in practice! ^^ Let's make it completely yours by solving algorithm problems together. Teacher Eun-jong will continue to be with you in Part 2.

Handling media (video, audio) on the web is now easier than ever! Learn the MediaStream API and WebRTC by following along step by step.

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.

Pass the Information Processing Engineer practical exam in one go! We pinpoint only the core code and theory for you. Master past exam questions perfectly! Open the door to passing with our systematic lectures. 🏆 2024 Inflearn Rookie Award 🏆 2025 Students' Pick Award

This course is designed to prepare you for the Information Processing Engineer practical exam solely through solving previous exam questions. Instead of unnecessary theories or vast amounts of content, it focuses on past exam questions that are repeatedly featured, allowing you to connect your learning directly to passing the exam. You can quickly grasp core points and question patterns by reflecting on the latest trends, and even learn tips for writing answers through the problem-solving process. This lecture is optimized for examinees aiming to pass efficiently in a short period of time.

Experience the power of Type Safe SQL with jOOQ!