The Secret to Passing 38 Companies, Essential Algorithms for 2025 Coding Tests

🎯 Coding Test Master Class perfected through 38 real-world passes

I have passed all coding tests for the companies listed below.

Naver, Kakao, Line, Coupang, Baemin, Daangn, Zigbang, Yanolja, Kakao Bank, MyRealTrip, Hyperconnect,

Kakao Mobility, Naver Webtoon, Works Mobile, Banksalad, Ohouse ...

You think this is an old story? I took coding tests until 2024 and changed jobs. I've experienced the coding tests of companies that are currently hiring. So I know what and how much you need to prepare.

Meaningless coding test study? You don't need that anymore. I'll teach you exactly what you need to know to get hired. Learn compactly and pass all your coding tests.

Collection of Real Reviews from Students Who Passed After Taking the Course

2025/02/16 TravelWallet Accepted **Hyun-nim

2025/07/31 Final acceptance from 3 companies - Mr./Ms. Oh

✅ Here's what you'll learn.

The characteristics of this course

📌For Beginners

• This course was created for complete beginners who have never learned algorithms before.

• I'll explain in detail why we write this code, how we come up with this approach, and how values change during actual execution. Starting from the thought process of why we use this code and how we arrive at this idea, I'll thoroughly explain how the values change when the code actually runs.

• Still, it might be hard to understand, so at the end of the video, I even included a visualization of the algorithm's solution method.

📌Just dive into problem-solving?Absolutely not

• Rather than simply solving problems, I'll teach you step-by-step, starting with the mindset of how to approach and solve problems when you see them.

• Algorithm problems are not designed for math geniuses to solve. Genius ideas? Eureka moments? Absolutely not.

• Each element that makes up a problem contains hints about the process to solve it. I'll show you how to pick up those hints.

📌 Community Management

• Nevertheless, you may have questions or things you don't understand.

• This can naturally occur due to the nature of online classes.

• So I created a community where you can ask questions and get answers in real-time.

• Feel free to come in and ask anything. Also, we hope you share algorithm solutions with various developers and solve problems together.

📌 60% Theory, 40% Practice

• Starting with detailed theoretical explanations, the curriculum ultimately progresses to solving actual problems from real company assessments.

We recommend this for:

🥳🥳🥳 Real Student Reviews 🥳🥳🥳

😨Concern Point 1😨.
I heard coding test languages are predetermined these days?

Is it true that the coding test language is predetermined based on the stack you're applying for, like JavaScript for frontend and Java for backend?

That's correct. There are cases where language is enforced.

I took coding tests at 38 companies and only got interviews at 2 places.

You can apply to almost any place you support without much language restriction.

Whatever you express it with, in the end, interviewers also know that the ability to solve problems is what matters.

😨Concern Point 2😨.
It's not my main language?

You might be worried because it's not a language you've already learned.

However, I think it's necessary to understand it most easily with Python.

Algorithms are already difficult, but when complex syntax and challenging logic are mixed together, the code becomes much harder to read.

When you first start studying, it's best to understand things as simply as possible, and then try expressing them in more complex ways later on.

It's also good to practice understanding through Python first, and then expressing it in your own language.

If you understand the logic in Python, you can definitely express it in Java.

😨Ultimately, language is a means of expression, and understanding the problem is what matters most.

And the easiest language to understand and solve problems with is Python.

[Updated July 20, 2025]

Many students have requested this, so I've added additional code solutions in Java and Javascript!
I haven't added explanations for these languages, but I think it would be great to review by looking at the same logic implemented in different languages!

🎁 EVENT 🎁

There are special benefits provided exclusively to those who take the course.

Based on 38 real coding tests I've taken, there are carefully selected special algorithm problems.

You can think of this as a special problem set created for those who want to do additional problem practice beyond theoretical learning.
This problem set will be continuously updated, so you'll be able to prepare for algorithms in line with current trends!!

(This problem set is provided as a link in Notion format!)

I'll provide a copy of this workbook to those who write course reviews!

Thank you.

Get it after verifying your course review in the Algorithm Community!

(The authentication method is written in the very last lecture __)

That's not all

Developer Job Preparation Guide (Resume, Portfolio, etc.) included!

🎁 EVENT 2 🎁

After completing the course, if you've been accepted, please share your course review + job transition success story in the open chat room!

Then, as a token of appreciation, I am sending you a coffee gift card.

🎁 EVENT 3 🎁

Please submit the Google form through this link

🎟 We'll provide you with a discount coupon 🎟

🎁 EVENT 4 🎁

PyCharm IDE 3-month free license provided!

To support your development studies, we've prepared special benefits through our collaboration with JetBrains.
With the promotion code below, you can use PyCharm for free for 3 months!

✅ Promotion Code: HYUNJOONPARKxJB
✅ Benefits: 3-month free license for a single JetBrains IDE (e.g., IntelliJ, PyCharm, WebStorm, etc.)
✅ Valid Until: May 13, 2026
✅ How to Use😀

1. Access the official JetBrains coupon registration page

2. Enter code and select your preferred IDE

3. Check the License Issued via Email

⚠ Warning:
This code is only available for new users who are using JetBrains for the first time.
(Only those who have never used a paid JetBrains license before can register)
(You can do this infinitely by creating new Google emails)

😆 Finally, I'll emphasize just two more things.

1. This course has undergone two thorough reviews, and all videos include subtitles.

"Why does that matter?" you might think, but many courses are uploaded without any review process.

This course has been refined through two rounds of review, carefully checking subtitles and context to enhance its completeness.

2. The textbook has a total of 393 pages.

The materials are designed so that you can fully understand the content through them alone. I have systematically organized and presented the content to help you save time and learn as efficiently as possible.

2024.11.30 Update

Among the lecture feedback, there was a comment saying "I wish there were more example problems."

I've added bonus problems throughout the course materials to reflect this.

🎆 Problems with this icon are bonus problems without separate explanation videos

2024.12.15 Update

Added textbook PDF download link

2025.1.13 Update

3-5. Additional Explanation on Further Improving the Stack - thanks to zz gg

1-5. Added explanation of the criteria for non-repeating characters as the first occurrence in finding the mode - thanks to Subin Oh

3-9. Added explanation for the condition that among songs with the same play count, songs with lower unique numbers should be included first - thanks to sonjs7554

2025.5.18 Update

4-2 Fixing Video Animation Errors - thanks to Aerong

2025.7.18 Update

3-3 Textbook Selection Sort Output Error Fix - thanks to Yu Gaebal

2025.7.20 Update

Java, Javascript problem-solving code added

2025.10.15 Update

Practical Data Structure Library Comparison Table - thanks to Brubru

2025.10.19 Update

Week 4 Homework #1 boundary value logic fix and boundary value test addition - thanks to 한달안에 끝낸다

2025.12.7 Update

4-8 DP section BigInteger code and explanation added - thanks to xuv2

2025.12.13 Update

5-4 Modifying Input/Output Cases - thanks to June

The person who created this course

• 2021 ~ 2022: S Coding Club Algorithm (data-structure) Tutor

• 2022 ~ : Operating coding YouTube channel DingCodingCo (featuring various content related to developer job hunting)

• 2022 ~ 2023 : Viva Republica Server Developer

• Never give up on students 🦈

• Operating the Developer Job Success Community

  
  

  • ✅ Join KakaoTalk Room: https://open.kakao.com/o/gPI6kTUg

    
    

  • ✅ Join Discord: https://discord.gg/X74q5Yw3Sv

    
    

Pre-enrollment Notes

If!! you have any hesitation before enrolling in the course.

Am I ready for this course?? If you're wondering about this, feel free to reach out anytime through the open chat room!

😍 I'll do my best to answer! 😍