I am a 7-year Spring developer who has been building my career mainly on SI projects. Since most of the processes for creating systems required by the nature of my work are CRUD tasks, I felt the limits of my growth and was preparing for a coding test to prepare for a leap forward and a job change. While I was originally subscribed to YouTube and watching videos, I found out that you opened a coding test lecture that was just what I needed. I have never used Python in practice, but I thought the problem-solving method itself would be the most important, so I started the sample lecture because the code was simple and I thought I would be able to adapt quickly. I think anyone can easily understand the concept of data structures thanks to the easy examples you provided, and I am grateful for the great lecture that you provided visualized data at the end so that even beginners can fully understand it. The part that I was most worried about during the job change process was the coding test, but thanks to Dingko, I think I can prepare a little more easily!