인프런 - 라이프타임 커리어 플랫폼

Solve everything from the basics of querydsl to practical use all at once!

For those who are new to JPA or who use JPA in practice but lack basic theory, By learning the basic theory of JPA solidly, even beginners can confidently use JPA in practice.

We will learn how to create a system to support large amounts of data and traffic by creating it directly with Spring Boot.

Experience the power of Type Safe SQL with jOOQ!

At some point in backend development, you start to have these concerns. It's that moment when services expand and traffic increases, and you begin to feel the limitations of simple REST communication and CRUD structures. I experienced these same issues in the field and went through much trial and error balancing performance and structural complexity. The solution I chose during that process was NATS. Its simple configuration based on a single binary, ultra-low latency performance in microseconds, and the fact that it provides essential features—from Pub/Sub to Queue Groups and JetStream—without being overkill made it a very practical choice for real-world service environments. This course is not just a list of NATS features. Based on the problems I faced in practice, I explain through code and workflows why I chose NATS in certain situations and how I designed the architecture. This course is designed to help everyone—from those new to messaging systems to backend developers preparing for employment and senior developers considering better architectures—understand distributed systems and grow to the next level.

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.

This course focuses more on data modeling through entity design than on JPA technical explanations. Based on the principle that solid DB design is the foundation of application development, we analyze various design patterns—such as one-to-many, many-to-many, inheritance, and collections—alongside business scenarios. You will learn by directly observing the process of code being transformed into actual tables on screen. To ensure immediate practical application, we provide business use cases, source code, and test codes for each design pattern.

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.

Build a scalable real-time event streaming order processing system using Spring Boot 3.x + Kotlin, establishing a Kafka cluster, and leveraging PostgreSQL CDC, Debezium Connect, and Apache Avro schemas.

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.

Most developers are still stuck on Batch and CronJobs when it comes to data processing. However, in real-world production environments, data is generated continuously, and failing to process that flow immediately leads to latency, bottlenecks, and consistency issues. Having personally dealt with real-time recommendations, state synchronization, and event delay problems in high-traffic environments, I’ve often asked myself, "Is batch processing really the right approach for this?" This course begins with that very question. It explores how to use Apache Flink to perform computations the moment data flows, manage state securely, and produce accurate results based on Event Time—all from a practical perspective. Beyond simple theoretical explanations, you will experience how real-time stream processing systems are designed and operated through actual source code and architectures. For those who found real-time processing vague or were curious about the world beyond messaging, this course will provide a clear sense of direction.

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.

If you can master DB and programming, you should be more than halfway prepared for the information processing engineer exam. Let's take a look at the DB and programming parts, which are worth 45 to 55 points in the practical exam, and pass the written exam steadily.

[Newbies to Web Development Only] Let's Build a Spring Boot REST API Step-by-Step, the Easy Way

This course covers the next level of JPA performance optimization beyond Fetch Join and batch_fetch_size. From JPA to Hibernate, JDBC, and the DB engine—you will understand the underlying operational principles and learn seven strategies that can create an 18x performance difference with a single line of configuration. Moving beyond Read optimization, you will tune the entire Spring Persistence layer, including Write performance, relationship pitfalls, and production testing environments. Vlad Mihalcea, a Java Champion and core Hibernate contributor, teaches based on his experience and the tools he personally created to overcome the limitations of Spring Data JPA.

From Java basics to advanced levels and Oracle SQL, this is a backend web development series where you learn through hands-on practice with star instructor Young-Cody Kim, who makes coding easy to understand even for non-majors and beginners.

We enable you to fundamentally understand and resolve issues where Hangeul appears broken on web pages or in databases, or files contain unknown characters.

Learn how to save, modify, delete, and query data in a database. Anyone, regardless of major, can easily follow along in just 30 minutes.

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!

This course is structured to help you learn Redis's basic commands using Lettuce, one of Java's official libraries, and to understand how to handle Redis at a low level.