Practical Algorithm Coding Test Problem Solving 100 Questions (by HaruCoding)

Step-by-step explanations that even beginners can easily understand make coding tests that once seemed daunting clear and approachable. Learn only what you need and apply it to real problems right away!

This course is for those who want to prepare for coding tests in the form of real mock exams. Each mock exam consists of 5 questions. It would be good to take my course, "Algorithm Problem Solving for IT Employment".

This course is for job seekers and career-changing backend developers preparing for coding tests with JAVA. We clearly identify question types by analyzing 195 actual past exam questions.

I hope that through this course you will gain a clearer understanding of grammar and gain confidence in solving problems.

Learn Java programming language by solving 100 problems. The entire course consists of 5 parts. In this course, Part 5, you will solve problems on topics such as certification (COS Pro Level 2), collections, and generic concepts.

Document writing is the most challenging part for both aspiring and current developers! Create your own portfolio by looking at how successful candidates write their documents! We speak based only on documents that actually passed!

Let's perfectly prepare for the second coding test (implementation test) by solving 10 problems created with reference to front-end coding tests given by actual companies!

Through training in thinking, expressing, and coding, you can easily understand and approach Java programming. You can understand the relationship between programming elements and gain confidence in future Java API utilization and projects through precise concept organization of object-oriented programming.

When learning Swift, the iOS programming language, it can be confusing when multiple concepts appear all at once. That's why I created this course with the principle that "when understanding a new concept, only previously learned concepts should be used." So this course is meticulously designed with a sequential structure between concepts, where only one new concept appears at each stage, and no other unfamiliar concepts appear at all. One concept per minute, 180 concepts total. From the basics of variables and constants to understanding memory structure from a CS perspective, and even the latest syntax for asynchronous processing. In 3 hours, you'll learn 180 core concepts in the designed order.

The Code Puzzle Clear Challenge is a 4-week intensive training course based on "Learn to Code 1" in Swift Playgrounds, designed to develop "computational thinking" by giving commands to make a computer move as intended. By solving puzzle missions in each session, participants naturally learn to break down problems into smaller steps (decomposition), recognize patterns to organize repetitive rules using for-loops or functions, and make logical judgments to change actions based on specific situations. Beyond simply finding the right answer, participants reach a level where they can explain and refine "why they solved it this way."

After using it for 14 days starting immediately upon release, here are the reasons why I recommend Claude Code (AI Coding) to everyone—from job seekers to industry professionals—as something they can apply right away.

This is a hands-on career and college admission project course where high school students use the AI-SPARS system to analyze their academic records, mock exam scores, and student record activities to explore their desired majors and universities. Students will compare various admission types, such as early and regular admissions, and personally design grade-specific roadmaps and execution strategies to reach their target universities. It is a practical course where high school students utilize AI-SPARS to analyze their grades and student record information while exploring desired majors, universities, departments, and college admission tracks. Participants will directly install and use the AI-SPARS program to create their own college admission profile and complete a strategic admission plan and roadmap to reach their target universities.

This is a career guide course that covers the entire process of landing a developer job or switching careers, including resumes, portfolios, technical interviews, and behavioral interviews. The theory section outlines the process of finding the right company for you, analyzing job postings, and preparing for interviews and coding tests.

We present various clean coding techniques.

Are you using code written by AI without even knowing what it does? It’s not enough for it to simply work—you need to make it perform well, yet when asked, “Why did you implement it this way?” you find yourself at a loss for words. The source of that frustration is a lack of fundamental CS knowledge and an understanding of how GPUs work. Through this course, you will learn the principles applied to CPUs and GPUs, along with the relevant CS knowledge, enabling you to control AI and give it instructions effectively. You will also be able to avoid being replaced by AI at your current company or when seeking employment or changing jobs, and earn a higher salary.

Even if you know nothing about coding, you can create your own scheduling app in just 4 weeks. Simply tell the AI, "Make an app like this," and paste the code you receive into Swift Playgrounds. Over 12 sessions—3 times a week, 30 minutes a day—you will complete a real app featuring adding/deleting/editing schedules, categories and notifications, filters and search, and even a calendar view. Don't worry if you run into errors; just ask the AI, and it will fix them for you. Start the challenge now to learn how to collaborate with AI, rather than just studying coding!

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

This is a game development & algorithm course that focuses on the algorithms and principles of 2D game development from the ground up using Windows API and C++.

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

This course goes beyond simple grammar explanations and focuses on developing C++ programming skills that can be applied immediately in the field. Throughout my teaching, I have directly addressed common challenges faced by many learners—such as struggling to understand the STL or feeling confused by file handling and exception handling concepts. Based on this experience, I provide step-by-step explanations to ensure even complex concepts are understood easily and clearly. Furthermore, this course is not just about delivering theory; it is structured around: 👉 "Why this concept is necessary" 👉 "How it is used in actual code" 👉 "How it is applied in professional practice"