Hello. I am Kim Young-han.
Finally, the full backend developer roadmap that I first set as a goal 7 years ago is now complete.
Following the completion of the entire roadmap and in response to many requests to reopen the Backend Master Pass, I am introducing Young-han Kim's Backend Master Pass for a limited time.
Link: https://inf.run/uixFt
With the release today of the final course, "Kim Young-han's Practical Database - Performance Optimization," I have now completed the entire roadmap, spanning from Practical Java to Spring, JPA, database design, and performance optimization.
It took seven years to reach this point after starting the very first lecture.
I would like to express my sincere gratitude to all of you who have been with me for such a long time.
A 7-Year Epic Journey, and Its Completion
When I first started the lecture, I had one goal.
Reflecting on the countless junior, mid-level, and senior developers I've met in the field, my goal was to consolidate all the practical skills necessary for developers to truly grow into a single, comprehensive roadmap.
Rather than merely explaining a single specific technology,
Fundamentals of Java and Object-Oriented Programming
Core Principles of Spring
Practical Development Using Spring Boot and JPA
Database Design
Large-Scale Data and Performance Optimization
I wanted to comprehensively cover all the topics that a backend developer inevitably encounters as they grow.
My goal was to properly put together the entire journey needed to grow from a newcomer to a junior, and then to a senior.
And now, seven years later, the entire roadmap I originally envisioned has finally been completed, culminating with the database performance optimization lecture.
Looking back, it has been a truly long journey.
While creating the lectures, I reshot the sessions countless times and constantly sought ways to deliver better explanations. I also meticulously deliberated and verified every detail to ensure that only the most essential content for real-world practice was included.
Honestly, maintaining something like this for so long is no easy feat. I, too, have fallen into slumps countless times and endured moments of sheer exhaustion and hardship. There were many days when I would come home after a hectic day at the office, completely drained, and record lectures late into the night.
Looking back, what got me back on my feet during those moments were each and every course review you left. All those messages where you took my lectures, cheered me on, and shared your stories of growth—like studying hard and landing a job at your dream company—were a tremendous source of strength for me. Those small words of encouragement that piled up over time were ultimately the greatest reason I was able to see this long journey through to the very end. Every time I read a review, and every time someone recognized me in passing and greeted me warmly, it gave me the strength to realize that the work I do is truly making a difference in someone's life.
Looking back, this entire process was never something I built alone. It was a time we created together, a journey we completed together.
I sincerely thank you.
Limited-Time Launch of the Backend Master Pass
In response to the completion of the entire roadmap and numerous requests to reopen the Backend Master Pass, we are pleased to introduce Kim Young-han's Backend Master Pass for a limited time only.
Link: https://inf.run/uixFt
This Master Pass is a comprehensive roadmap that covers everything from the fundamentals to real-world practice for backend developers, all the way to the system design and performance optimization that senior developers need to tackle.
Pass Product Configuration — Integrating 4 Core Roadmaps
The Backend Master Pass includes the following 4 complete roadmaps.
Kim Young-han's Practical Java Roadmap
Kim Young-han's Complete Spring Mastery Roadmap
Kim Young-han's Complete Mastery Roadmap for Spring Boot and JPA in Practice
Kim Young-han's Practical Database Roadmap
You can learn everything in one seamless learning path, starting from Java's basic syntax and object-oriented programming, and progressing to Spring, JPA, database design, and performance optimization.
This time around, the entire Backend Master roadmap has been completed with the official addition of the final piece of the puzzle: "Kim Young-han's Practical Database - Performance Optimization."
The Last Puzzle, Database Performance Optimization
As your service grows and data begins to accumulate, you will inevitably encounter database performance issues.
Queries that run smoothly during development can suddenly slow down in the production environment, and even a single simple query can sometimes become a bottleneck or cause an outage across the entire service.
What is needed at this point is not simply a quick fix of adding a few indexes.
You need to understand how the database stores and retrieves data, how to analyze execution plans, and why the optimizer chooses a specific index and join order.
This performance optimization lecture covers the following topics.
Analyzing Execution Plans Using EXPLAIN and EXPLAIN ANALYZE
B+Tree and the Internal Structure of Indexes
Clustered Index and Secondary Index
Principles of Composite Index Design
Diagnosing and Optimizing Using filesort
ICP, Covering Index, Skip Scan
Optimizer and Histogram
Join and Random Access Optimization
Sorting, Paging, and Grouping Performance Optimization
Large-Scale Statistics Processing Using Pre-Aggregated Tables
Now, you have completed the entire journey, moving beyond just building applications properly to directly analyzing and resolving the performance issues that arise as your service scales.
Why a Comprehensive Roadmap is Needed in the AI Era
As we enter an era where AI writes code, a developer's foundational skills are becoming more important than ever.
AI is not a tool that replaces a developer's capabilities, but rather one that amplifies them.
Developers with solid fundamentals can ask AI better questions and verify whether the results it generates are correct.
Conversely, without a solid foundation, even if the code appears to work on the surface, it is difficult to detect the following problems.
Code with broken object-oriented design
A structure difficult to maintain
Improper transaction handling
Inefficient data access
Queries that cause failures in production
A design that slows down as data grows
AI technologies and tools will continue to evolve, but the fundamentals remain unchanged: the ability to distinguish good code from bad, the principles of object-oriented programming, how HTTP and the web work, transactions, and database design and performance optimization.
Only when you truly understand can you ask the right questions, verify your work, and refine your approach to achieve better results.
This Backend Master Pass captures the very essence of what remains unchanged.
Continuous Course Renewal
The entire roadmap is complete, but lecture production is not yet finished.
Going forward, we plan to continuously update our existing courses to keep pace with technological advancements and real-world work environments.
As needed, we will carry out full and partial video renewals, as well as updates to the manuals and example projects.
Those who purchase the Master Pass will have continuous access to all updated content at no additional cost, even if the lectures are renewed or prices change in the future.
It is the very least courtesy and a promise to those who trusted me and chose me.
Lastly,
This pass is not merely a bundle of multiple courses.
This is the culmination of everything I have learned, the failures I have faced, and the challenges I have wrestled with over years of hands-on experience, all distilled into a single growth journey.
I will be your steadfast guide as you progress from a newcomer to a junior, and from a junior to a senior, until the day you become the kind of developer your colleagues truly want to work with.
Thank you.