The secret to passing 38 companies: Essential algorithms for the 2026 coding test

Hello everyone! This is Dingcodingco 🙌

These days, as I run various challenges on Inflearn,
I’ve been meeting and talking with so many of you.

Those I’ve met on live streams,
those I’ve met in person offline,
and everyone joining me online!

Thanks to the passion and support you send me,
I gain so much energy every time as well. Thank you so much 😊

To give back a little of my gratitude
, I’ve prepared a 25% discount event on all Dingcodingco courses! (Until 9/13)

If there was a course you needed, please take advantage of this opportunity :)
Thank you for always being with us! 🙇

Hello, this is Dingco Dingco!!! 👋👋

To express my gratitude to those who have taken Dingco Dingco courses and supported me, I am releasing 11 types of free materials.

At DingcoDingco, we place great importance on fundamental skills that last a long time.

That's why I've made these materials available, hoping that more people can first experience the fundamental resources that last a long time once established, such as Web Security, TDD, Clean Code, and Basic Web Development.

The materials released this time include not only simple summaries but also textbook-style materials used in actual classes.

Public Materials

- Basic Web Development Concepts Textbook: Internet/Web, Client/Server, HTTP, JSON 🌐

- Web Security Textbook: Encryption, HTTPS/SSL, Cookies/Sessions, JWT, OAuth 🔐

- TDD Textbook: JUnit5, Mockito, Spring Testing, Functional Testing, Refactoring

- Clean Code Textbook: Naming, Function Separation, Exception Handling, Refactoring, Practice Assignments

- JPA Interview 20 Questions

- Spring Boot Interview 18 Questions

- 23 Selected Technical Interview Questions for Entry-level Backend Developers

- Backend Interview Notion Workbook

- Latest Algorithm Exam Questions Notes

- DB Worksheet

- Git Cheat Sheet

I have organized both free material coupons and lecture discount coupons in the KakaoTalk channel coupon box.

Please feel free to take any materials you need!!! ❤️
I hope these serve as a guide for those just starting their studies and as a checkpoint for those already studying to identify any missing areas.

For those who wish to continue their studies more systematically, I also recommend checking out each lecture along with the roadmap!

- KakaoTalk Coupon Box: https://pf.kakao.com/_xhwxfPX/coupons?filter=usable

- List of free materials: https://dingco.net/free-guides

Hello, this is Dingco Dingco!

I have launched the Introductory SQL/DB Course. And this course is completely free!

"When I open a book to study SQL, it's 300 pages long—what do people actually use in the real world?"

I have packed the answer to this question into just 2 hours.

30% off all courses to celebrate the launch

To celebrate the launch of the free course, I am offering a 30% discount on all my other courses for two weeks.

• Period: 7 days from today

• Applicable to: All paid courses by DingcoDingco

• Discount Rate: 30%

Master the basics of SQL with the free course, and if you need more in-depth learning, take this opportunity to dive deeper!

Thanks to your constant support, I have released another course. I will continue to provide content that can answer the question, "So, how is this actually used in practice?"

Thank you!

Best regards, Dingco Dingco

Hello, this is Dingcodingco

Thank you so much for taking the course and writing various reviews!!!

I was wondering if I could turn my heart of encouragement and gratitude into a class review event.

For those who have taken more than 80% of the course and written a review on their blog

I would like to give away a Coupang Eats 30,000 won gift certificate!!!

Chicken is expensive, but one is probably enough for you 🍗 🍗 🍗

There are a few annoying conditions, but I really want to eat chicken!

Wow, I really wanted to write a review of the lecture, but for those of you who think you should do it,

Please apply through the link. Thank you. Have a nice evening!! 🥰 🥰 🥰

https://forms.gle/yjHtKDGCNXMrxHmM9

https://forms.gle/yjHtKDGCNXMrxHmM9

Hello everyone, this is Dingcodingco!!

In support of your development studies, we have prepared special benefits in collaboration with JetBrains .
Get 3 months free access to any single IDE from JetBrains, including IntelliJ and Pycharm, with the promo code below!

⚠ Note :
This code is only available to new users who are new to JetBrains .
(Only those who have not previously used a JetBrains paid license can register)

(So, you can just create a new Google email...)

✅ Promo Code : HYUNJOONPARKxJB
✅ Benefits : 3 months free access to JetBrains single IDE (e.g. IntelliJ, PyCharm, WebStorm, etc.)
✅ Expiration date : Until May 13, 2026
✅ How to use :

1. Go to JetBrains official coupon registration page

2. Enter the code and select the IDE you want (only one can be selected😭)

3. Verify the license issued by email

We are also preparing additional benefits for those who have already used JetBrains tools, so please use the code a lot so that we can provide more benefits in the future 🙌

🧑‍🏫 This is a great opportunity for those who wanted to experience the tools or settings used in the lecture firsthand.
Be sure to take it with you!