CS Interview Preparation - Database Edition: Insights Directly from Channel Talk Interviewers

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.

(5.0) 3 reviews

148 learners

Level Basic

Course period Unlimited

DBMS/RDBMS
DBMS/RDBMS
NoSQL
NoSQL
computer-science
computer-science
DBMS/RDBMS
DBMS/RDBMS
NoSQL
NoSQL
computer-science
computer-science

Reviews from Early Learners

5.0

5.0

์กฐ๋งŒ๊ธฐ

100% enrolled

I thought I had studied the theory well enough, but when I imagined myself in an actual interview, I felt like I couldn't organize my answers properly. This lecture was great because it addressed exactly those pain points. It was particularly helpful how it showed not just simple memorization of database concepts, but how to answer actual questions structurally. Overall, I am highly satisfied as the content can be applied directly to real-world situations, and I look forward to other lectures on different topics in the same format.

5.0

์šฐํ˜์ค€

79% enrolled

Whenever I prepared for interviews, I had a decent understanding of the concepts, but I always struggled with how to actually explain them in words. Through this lecture, I was able to go beyond just organizing database knowledge and get a feel for the flow of how to answer during an interview. It was especially helpful because it presented frequently asked topics like real-world interview questions. If other CS topic lectures are released in a similar format, I would definitely love to take them..!

5.0

์€๋ฏธ

100% enrolled

Just as the course title suggests, I liked how it pinpointed the exact topics likely to be asked in an actual interview. It helped me prepare for real-world scenarios by organizing not just the theoretical knowledge of databases, but also "how to explain it" effectively. I was particularly impressed with how common topics like transactions, indexes, and normalization were explained from an interviewer's perspective. It is a highly efficient course for the amount of time invested!

What you will gain after the course

  • A perfect model answer as evaluated by an interviewer

  • The same question: the decisive difference between a failing answer and a passing answer

  • Full set of actual interview questions and follow-up question pedigrees for Naver, Kakao, Line, Coupang, Baemin, Danggeun, Toss, and Unicorn companies (over 100 questions)

  • Answering skills that make you say "I nailed the interview" instead of "I blew the interview"

๐Ÿคฌ Database interviewsโ€”I definitely know all the content, so why can't I get the words out?!

I'm Jayon, currently working as a backend engineer and interviewer at Channel Talk, after completing the Woowa Course and working as a backend engineer at several companies. I wasn't someone who was good at interviews from the start. In fact, I ranked near the bottom in the Woowa Course mock interviews and even had to have a separate meeting with the CEO.


Transaction isolation levels? I knew them. Index operating principles? Of course, I had them organized. But everything changed once I sat down in the interview room.

"Please explain the types of transaction isolation levels." Up to this point, it was fine. I recited everything just as I had prepared. But the moment the interviewer pointed to one of my answers and asked, "Then how is Phantom Read resolved in REPEATABLE READ?" my mind went completely blank. I had definitely seen it somewhere. I had even summarized it. But in that moment, sitting right there, I just didn't know what to say.

Searching it on my phone after the interview and thinking, "Ah, it was this..." That feeling of emptiness... I'm sure many of you can relate.


From that point on, I started recording and reviewing my interviews. I created "incorrect answer notes" and compared my previous answers with my current ones for the same questions. As I accumulated over hundreds of questions and answers, patterns began to emerge. I started to see which answers convinced the interviewers and which ones invited unnecessary follow-up questions.


It was only after going through this trial and error hundreds of times that I realized: knowing the theory and speaking in an interview are completely different skills. That's why I decided to create a lecture focused solely on "how to answer the questions."

โœจ 4 Key Points I Focused on While Creating the Course

This is not a theoretical summary lecture. Lectures that summarize "what an index is" can be easily found just by looking at blogs. This lecture teaches you, "If the interviewer asks this, answer like this." Each lecture corresponds to one interview question, and we break down step-by-step how you should answer that question.

We compare and analyze three levels of answersโ€”Bronze, Silver, and Goldโ€”for the same question.Bronze is a 50-point answer out of 100, Silver is an 80-point answer, and Gold is a 100-point answer. We show you the specific differences in why some pass and others fail, even when using the same keywords.

The content is based on actual past exam questions from major corporations and unicorn startups. It includes not only the main questions but also the follow-up questions that actually follow. From the main question to the follow-up and the follow-up to that, the lecture is structured exactly the way questions flow in a real interview.

Frequently asked questions are provided as a supplementary PDF and are continuously updated. Frequently asked questions that couldn't be covered in the lecture are provided in a separate PDF, and we plan to keep adding more in the future. Once you purchase, you can continue to receive all updated supplements.

๐Ÿ‘ This is recommended for the following people!

Those who can answer the initial question but find their mind going blank when follow-up questions start.

Those who want to know the interviewer's inner thoughts, wondering, "What will they think when they hear this answer?"

Those who want to be hired by IT service companies like Kakao, Naver, LINE, and Toss

๐Ÿก Preview

'What is a transaction, and please explain ACID' During class


'If a failure occurs in the DB, in what order do you approach it?' during class


'(Follow-up question) Why is B-Tree used as the data structure for indexes instead of a Hash Table?' From the class


โœ” Notes

  1. The class proceeds on the assumption that you have at least a basic understanding of database fundamentals. The effectiveness of the lecture will be maximized if you have been exposed to concepts such as transactions and indexes at least once.

  2. If you happen to encounter any parts you don't understand while studying, please ask immediately by using the Q&A board๐Ÿ˜Š


๐Ÿšจ Be sure to check who the person providing the education is!

If you meet the wrong doctor, you may die because you cannot cure your illness at that moment. However, death ends with the pain of that moment. But if you meet the wrong teacher and receive a poor education, you will suffer for the rest of your life.

Due to poor education, you may end up at a company you didn't want, receive a smaller salary than expected, and suffer for the rest of your life as a result. Not only that, but the poor education you received can even be passed down to your children.

I believe that education can truly change a person's life for the better, but on the other hand, it can also completely ruin a person's life. That is why I believe education carries such a heavy responsibility.

Therefore, please check who the educator is, what kind of person they are, and what path they have taken, and make a careful decision.

๐Ÿ‘‹ Hello!
I'm finally introducing myself ( โธโธโ€ขแด—โ€ขโธโธ )เฉญโพโพ

Hello!

I am Jayon, a 5th-year developer working as a backend engineer at Channel Talk.

I completed the Woowa Course 3rd Backend program and started my career at a small SI company. My salary was at the minimum level. To escape that situation, I poured a tremendous amount of time into preparing for coding tests and interviews. As a result, after passing through Chai Corporation (PortOne), I am currently earning several times my initial salary while managing Channel Talk's core system, which handles billions of records.

I felt it while going through this process: it is truly difficult to find the right direction when preparing for a job alone. That is why I have been active as a backend mentor at F-Lab, JSCODE, and Fast Campus, and also served as a reviewer for the 5th Woowa Tech Course. Through mentoring, I have produced successful candidates for companies like Naver, Kakao, Line, Coupang, Baemin, Danggeun, Toss, unicorn startups, and major corporations, and the know-how accumulated during that process is fully contained in this lecture.

Just as I received a lot of help when I was going through difficult times, I wanted to become someone who could help many others as well. I felt most proud and happy when the value I created through development had a positive impact on other people.

I also run a technical blog steady-coding, so if you're curious about what kind of developer I am, please feel free to visit!

Thank you!

๐ŸšŒ If you're feeling overwhelmed about which order to take the courses in?

Please refer to '[2026] Essential Curriculum for Becoming a Backend Developer (IT Service Companies)'!!


๐Ÿถ Get course discounts with the roadmap

โžก CS interview preparation tips directly from a Channel Talk interviewer

(https://inf.run/8VEbS)

Recommended for
these people

Who is this course right for?

  • Those who want to be hired by IT service companies like Kakao, Naver, LINE, and Toss

  • Those who want to cram for a database interview in 3 hours right before the interview.

  • Those who are curious about frequently asked interview questions and the scoring criteria.

  • Those who want to know the inner thoughts of an interviewer, such as "What would they think if they heard this answer?"

  • Those who have never done a CS interview before and don't even have a sense of what kind of questions will be asked.

  • Those who can answer the initial question but find their mind going blank when follow-up questions are asked.

Hello
This is jayon0927

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[Career]

Current) Channel Corporation - Lv 4. Backend Engineer

Former) Chai Corporation (PortOne) - Backend Engineer

 

[Education]

Current) F-Lab Backend Mentor

Current) JSCODE Backend Mentor

Former) Woowa Tech Course 5th Gen Backend Reviewer & 3rd Gen Backend Graduate

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Curriculum

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53 lectures โˆ™ (2hr 54min)

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Reviews

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3 reviews

5.0

3 reviews

  • whjoon02250801๋‹˜์˜ ํ”„๋กœํ•„ ์ด๋ฏธ์ง€
    whjoon02250801

    Reviews 2

    โˆ™

    Average Rating 5.0

    5

    79% enrolled

    Whenever I prepared for interviews, I had a decent understanding of the concepts, but I always struggled with how to actually explain them in words. Through this lecture, I was able to go beyond just organizing database knowledge and get a feel for the flow of how to answer during an interview. It was especially helpful because it presented frequently asked topics like real-world interview questions. If other CS topic lectures are released in a similar format, I would definitely love to take them..!

    • jayon0927
      Instructor

      Hello, Hyukjun Woo! Thank you for leaving such a valuable review๐Ÿ˜Š Knowing a concept and being able to explain it naturally in an interview are definitely two different things, so I'm glad to hear it was helpful in that regard. It's also very encouraging to hear that the flow of the practical questions resonated with you. As you mentioned, I am preparing other CS topics in the same manner, so I will continue to do my best to be of great help. Thank you!

  • eunmi21652388๋‹˜์˜ ํ”„๋กœํ•„ ์ด๋ฏธ์ง€
    eunmi21652388

    Reviews 2

    โˆ™

    Average Rating 5.0

    5

    100% enrolled

    Just as the course title suggests, I liked how it pinpointed the exact topics likely to be asked in an actual interview. It helped me prepare for real-world scenarios by organizing not just the theoretical knowledge of databases, but also "how to explain it" effectively. I was particularly impressed with how common topics like transactions, indexes, and normalization were explained from an interviewer's perspective. It is a highly efficient course for the amount of time invested!

    • jayon0927
      Instructor

      Hello, Eunmi! Thank you for leaving such a great review๐Ÿ˜Š I'm truly glad to hear that it helped you with how to actually answer during interviews. For frequently asked topics like transactions, indexes, and normalization that you mentioned, it will be even more helpful if you keep reviewing them and organize them in your own words. I will continue to strive to provide content that you can apply directly in practice. Thank you!

  • zkspffh2776๋‹˜์˜ ํ”„๋กœํ•„ ์ด๋ฏธ์ง€
    zkspffh2776

    Reviews 2

    โˆ™

    Average Rating 5.0

    5

    100% enrolled

    I thought I had studied the theory well enough, but when I imagined myself in an actual interview, I felt like I couldn't organize my answers properly. This lecture was great because it addressed exactly those pain points. It was particularly helpful how it showed not just simple memorization of database concepts, but how to answer actual questions structurally. Overall, I am highly satisfied as the content can be applied directly to real-world situations, and I look forward to other lectures on different topics in the same format.

    • jayon0927
      Instructor

      Hello, Mangi Jo! Thank you for leaving such a valuable review๐Ÿ˜Š In order to give good answers during an interview, the ability to structure and speak what you know is quite important. I am glad to see that you understood that well. I will be rooting for you in your future endeavors!

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