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[Lv1] Spring Boot You Can 'Explain' in Interviews - Backend Development Answered with Experience

This is an introductory backend development course where you learn through understanding rather than memorization, and experience rather than theory. Instead of reciting a Googled definition when asked "What is JPA?" in an interview, this course will empower you to give an answer based on experience, starting with "Well, I've been through JdbcTemplate hell..." You will gain a deep, intuitive understanding of "why we use frameworks" by experiencing firsthand how 30 lines of pure Java ServerSocket code shrink down to just 7 lines in Spring Boot. After 6 sessions, you will walk away with a functional portfolio piece: a Todo List REST API built with Spring Boot + JPA.

(5.0) 37 reviews

235 learners

Level Basic

Course period Unlimited

Spring
Spring
Spring Boot
Spring Boot
JPA
JPA
hibernate
hibernate
Spring
Spring
Spring Boot
Spring Boot
JPA
JPA
hibernate
hibernate

Reviews from Early Learners

Reviews from Early Learners

5.0

5.0

창근

33% enrolled

I ended up taking this course almost by force (?) because my company suddenly started using Spring, but looking back, I don't know what I would have done if I hadn't taken it. I wasn't a complete beginner to backend development, as I had experience with NestJS, so I was worried that Spring might feel too heavy or frustrating. However, those worries were completely shattered from the very first lecture. The flow—from Spring's philosophy to its architecture and why it was designed this way—was so smooth that I lost count of how many "Aha!" moments I had. It doesn't just list syntax; it builds the practical intuition and fundamentals needed in the field. Even coming from a NestJS background, it was great to understand Spring by comparing the two. I can confidently say that for those new to Spring, as well as those like me who have experience with other frameworks but have never properly learned Spring, this single course will completely wash away any vague fears you have. It's hard to find a better course than this for solidifying your fundamentals.

5.0

김민구

39% enrolled

This would be great for people who are new to Spring Boot, just learned Java, or learned it a long time ago. Also, Dingcodingco explains really well so it's easy to understand.

5.0

fain9301

98% enrolled

Thank you for the great lecture.

What you will gain after the course

  • The ability to answer with "experience" in backend interviews

  • Practical Spring Boot + JPA development skills

  • A learning experience of internalizing the "Why"

  • An eye for reading production code

  • The tech stack required by 95% of entry-level backend developer job postings

If you learn Spring this way, you will fail the interview

I turn on the lecture and just type along.

Add @RestController, add @GetMapping... Oh, it works! Portfolio complete!

But this is how they ask in the interview

"What is JPA?"

"Um... it's for using databases with Java... uh... well..."

You will fail.

"Have you done a Spring Boot project?"

"Yes! I followed along with a YouTube video... but to be honest, as for why IoC is necessary..."

You find yourself unable to explain a project you built through copy-pasting.


Most Spring courses only teach "how to use it".

"JPA is used like this. Just call save()."
"For transactions, just add @Transactional."

If you follow along, it works. You can even build a portfolio.

But interviewers ask "why."

"Why do you use JPA?"

"Why is a transaction necessary?"

"Why do you separate the Controller and the Service?"

People who have only learned the "How" answer like this:

"JPA is an ORM... and if you use save(), it gets saved..."

That's it. There's nothing more to say.

It's because they've never experienced it. Since they've never done it without JPA, they don't know why JPA is even necessary.


That's why this lecture gives you "pain" first.

To learn Spring properly, you shouldn't learn the convenient things first. You have to experience the uncomfortable things first.

If you build a web server using pure Java, it takes 30 lines. You have to write the HTTP response by hand. As a string. You are literally typing out "HTTP/1.1 200 OK" yourself.

What happens when you see Spring Boot after going through that pain? It's finished in 7 lines. The exact same thing runs.

At this moment, it becomes like this: "Ah... so this is why people use Spring Boot."

JPA is the same. If you connect to a DB without JPA, you have to write the SQL strings yourself, and the code just to convert the query results into Java objects takes 50 lines.

This "pain → salvation" experience makes you a "developer who can explain."

✅ Here is what you will learn.

🍽️ Backend concepts understood through a restaurant analogy

  • Clerk-Manager-Warehouse Keeper analogy for understanding 3-tier architecture

  • Ordering a burger combo to understand transactions (Give both, or give nothing)

  • Singer and manager analogy for understanding the Proxy Pattern

  • Metaphors and explanations that are impossible to forget once you've heard them.



🌱 A course truly designed for absolute beginners

  • "Why we are learning this" - every conceptual explanation starts from here

  • If you know Java if and for statements, you're OK; even if you don't know Spring Boot, you're OK.

  • "Pain → Salvation" Learning Method: You must experience the 30 lines of pain in ServerSocket to realize the greatness of 7 lines in Spring Boot

  • Step-by-step practical exercises that even non-majors can follow


✨ Features of this course

📌 Constantly asking "Why?"

This course doesn't just end with "do it this way."

Typical lecture: "JPA is an ORM. Just use save()." (X)


This course: After personally experiencing the 50-line hell of SQL + RowMapper with JdbcTemplate,

Deeply experiencing why a single line of JPA's save() is revolutionary.

Every concept begins with "Why was this technology created?" Once you internalize the "Why," the "How" follows naturally.


📌 "Pain → Salvation" Learning Method

This is not a lecture that simply gives you the answers. It intentionally makes you experience the pain first, then lets you truly feel the greatness of the solution.

Session 2: 30 lines of ServerSocket for HTTP parsing vs. 7 lines of Spring Boot

Session 3: JdbcTemplate SQL + RowMapper hell, JPA save() in one line

Session 4: "I didn't write the code, so why is it working?" Confusion. Perfect understanding through the Proxy Pattern.

Session 5: Controller overworking by doing everything—clean structure through 3-tier separation

This experience will enable you to start your interview answers with "In my own experience..."

You will be able to explain Spring, Spring Boot, JPA, and Hibernate.


📌 Answering techniques that prompt follow-up questions from interviewers

Lectures that just throw concepts at you and end there, lectures where you have no idea how to actually use the material in an interview… I hated those kinds of lectures the most.

This course connects concepts → hands-on experience → interview answers.
(The image below shows the interview success content from the Backend Resume Differentiation Course)

Recommended for these people

I know Java basics, but the idea of building a "server" feels vague
✔ Those who know if and for statements but don't know what to build with them
✔ Those who want to start step-by-step from "Hello World"


I followed along with YouTube, but I can't explain it in an interview
✔ Those who don't understand the principles behind projects made by copy-pasting
✔ Those who want to become developers who can explain "why the code should be written this way"

I want to prepare for interviews and practice at the same time
✔ Those who want to answer common technical interview questions based on "experience"
✔ Those who want to learn Spring Boot through practical application rather than just theory

🗺️ This course is Lv.1

This course is the starting point. Based on this, I am creating a backend developer roadmap.

Lv.0 Core Database Concepts - Building Foundations Before Starting Spring

Lv.1 Introduction to Spring Boot (This Course) - Building APIs with Spring, Interview Preparation

Lv.2 Professional Developer's Complete Mastery of JPA - From Persistence Context to Practical Patterns

Lv.3 Deployment (AWS, CI/CD) Releasing to the real world, not just localhost

Lv.5~6 Architecture & Practical Projects: Building MSA, DDD, and E-commerce Systems

Let's start with this lecture and move forward together step by step!

Spring Boot Lv3 Thumbnail

🎁 EVENT 🎁

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

[Lv1] 18 Spring Boot Interview Questions workbook is provided

(This workbook is provided as a Notion link!)

We will provide the textbook to the first 100 people who write a course review!

Get it after verifying your course review in the community!

(I have included the instructions on how to verify in the very last lecture __)


🎁 EVENT 2 🎁

If you submit the Google Form via this link,

🎟 We will send you a 15% discount coupon 🎟

🎁 EVENT 3 🎁

Get a 3-month free trial of IntelliJ IDE!

To support your development studies, I have prepared special benefits through a collaboration with JetBrains.
You can use IntelliJ for free for 3 months using the promotion code below!


Promotion Code: HYUNJOONPARKxJB
Benefit Details: JetBrains Single IDE (e.g., IntelliJ, PyCharm, WebStorm, etc.) 3-month free trial
Expiration Date: ~ Until May 13, 2026
How to Use😀

1. Access the official JetBrains coupon registration page

2. Enter the code and select the IDE of your choice

3. Check the license issued via email


Precautions:
This code is only available for new users who are using JetBrains for the first time.
(Only those with no prior history of using a paid JetBrains license can register)
(You can do this indefinitely by creating a new Google email account)

The person who created this course

Sharing the behind-the-scenes story of reaching the final interviews at Coupang and Yanolja - A 6th-year developer's story of applying to 24 companies [ep 5]

Dingcodingco (Main Instructor)

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

  • 2022 ~ : Operating the coding YouTube channel Dingco Dingco (Featuring various content related to developer employment)

  • 2022 ~ 2023 : Viva Republica Server Developer


  • Never giving up on a student 🦈

  • Operating a developer career-cracking community and organizing offline meetups


Things to note before taking the course

If!! you are having even the slightest hesitation before signing up for the course.

Is this the right course for me to take right now? If you are having such concerns, please feel free to contact us anytime via the Open Chat Room!

😍 I will do my best to answer your questions 😍

Practice Environment

  • We use IntelliJ. The Community (free) version is perfectly fine.

  • It doesn't matter whether you use Windows or Mac! We provide installation guides for each operating system.


Learning Materials

  • Everything will be shared via Notion and PDF!

  • We will share the project code with you!

Prerequisites and Important Notes

  • Those who have experience learning Java

  • Those with experience in MySQL CRUD (It's okay if you don't know it. We provide free database educational materials!)


Recommended for
these people

Who is this course right for?

  • Those who know Java basics (if, for, class) but find the idea of building a 'server' with them vague.

  • Those who can get the code running by following YouTube tutorials but can't explain it in an interview.

  • New job seekers intimidated by "Spring Boot and JPA experience preferred" in job postings

  • Those who have read Spring Boot books but struggle with real-world application

  • Those who completed a coding bootcamp but know the "how" without understanding the "why"

Need to know before starting?

  • Basic Java syntax level (Having completed one introductory Java course is sufficient)

  • Database Knowledge (Free educational materials provided upon participating in the course review event!)

Hello
This is dingcodingco

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Learners

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Reviews

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Answers

4.9

Rating

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Courses

🚀 Toss, POSTECH graduate | 8 years backend
🎥20K YouTuber | Creating dev content
📚 Inflearn instructor | 14,000+ cumulative students
👥 Running developer job community (8,000+)
🧩 Multiple open source contributor (Gradle, Spring AI, etc.)
📝38 document screening passes & 100+ resume reviews on Kmong (5.0 rating)

Flipping coding upside down, DingCodingCo. Delivering knowledge that's easy and deductively understandable.
Đảo ngược lập trình, Dingco Dingco. Truyền đạt kiến thức một cách dễ hiểu và có tính suy luận.

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Curriculum

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42 lectures ∙ (9hr 58min)

Published: 
Last updated: 

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37 reviews

5.0

37 reviews

  • sasas님의 프로필 이미지
    sasas

    Reviews 81

    Average Rating 5.0

    5

    31% enrolled

    • fain9301님의 프로필 이미지
      fain9301

      Reviews 98

      Average Rating 4.8

      5

      98% enrolled

      Thank you for the great lecture.

      • lich11158962님의 프로필 이미지
        lich11158962

        Reviews 2

        Average Rating 5.0

        5

        33% enrolled

        I ended up taking this course almost by force (?) because my company suddenly started using Spring, but looking back, I don't know what I would have done if I hadn't taken it. I wasn't a complete beginner to backend development, as I had experience with NestJS, so I was worried that Spring might feel too heavy or frustrating. However, those worries were completely shattered from the very first lecture. The flow—from Spring's philosophy to its architecture and why it was designed this way—was so smooth that I lost count of how many "Aha!" moments I had. It doesn't just list syntax; it builds the practical intuition and fundamentals needed in the field. Even coming from a NestJS background, it was great to understand Spring by comparing the two. I can confidently say that for those new to Spring, as well as those like me who have experience with other frameworks but have never properly learned Spring, this single course will completely wash away any vague fears you have. It's hard to find a better course than this for solidifying your fundamentals.

        • kmk8422님의 프로필 이미지
          kmk8422

          Reviews 2

          Average Rating 5.0

          5

          39% enrolled

          This would be great for people who are new to Spring Boot, just learned Java, or learned it a long time ago. Also, Dingcodingco explains really well so it's easy to understand.

          • jhm03508571님의 프로필 이미지
            jhm03508571

            Reviews 1

            Average Rating 5.0

            5

            100% enrolled

            I am preparing to become an AI developer and took this course because I felt the need for backend knowledge. Although I learned the basics, I was able to find a clear direction on what to focus on in an era where AI writes code for us. Through this lecture, I feel like I learned how to start building a perfect project rather than just finishing one. I will definitely take the follow-up courses even after I get a job. Thank you for the great class!!

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