I'm transferring the course completion review I left on LinkedIn to Inflearn as well. https://www.linkedin.com/posts/arawn_%EA%B8%B0%EB%8B%A4%EB%A6%AC%EB%8D%98-%EC%9D%B4%EC%9D%BC%EB%AF%BC%EB%8B%98%EC%9D%98-%EC%8B%9C%EB%A6%AC%EC%A6%88-%EA%B0%95%EC%9D%98-%EB%A1%9C%EB%93%9C%EB%A7%B5-%ED%86%A0%EB%B9%84%EC%9D%98-%ED%81%B4%EB%A6%B0-%EC%8A%A4%ED%94%84%EB%A7%81%EC%9D%98-%EC%B2%AB-%EC%A3%BC%EC%A0%9C%EC%9D%B8-activity-7352614457123987456-pleA?utm_source=share&utm_medium=member_desktop&rcm=ACoAABvezLwBBEWVnGUkIY_xxm2aE3-sGtVHt0g -- Lee Il-min's lecture once again did not disappoint. His characteristically thoughtful and kind explanations, as well as the way he calmly unfolds his thought process through live coding, were particularly excellent. The way he proceeds by pointing out what he's thinking and with what intention he's writing code was truly admirable. Following the lecture, I could feel an immersive experience as if I had become the instructor myself, experiencing his thought process firsthand, and through this, I naturally came to understand how to apply domain model patterns and hexagonal architecture when developing applications with Java and Spring. While the technical depth was outstanding, what particularly impressed me about this lecture was how it demonstrated the 'attitude toward technology' and 'learning methods' of a professional. First, it clearly presents the correct approach to technology learning. When explaining hexagonal architecture, the content is developed based on the original text and core arguments of Alistair Cockburn, who first proposed it. This seems like an obvious approach, but in reality, many people encounter technology through secondary or tertiary processed content rather than primary sources. While processed materials can be useful for understanding, there's also a risk that the original author's intent may be diluted or distorted. It reminded me once again that to understand the essence of technology, we should access original sources whenever possible. Second, I could truly appreciate the importance of having a thinking approach equipped with one's own logic. For example, in the "Entity vs DTO" class, he logically demonstrated his views on why using entities in the presentation layer is not problematic. As developers, when we make any technical decision, we should be able to explain the reasons with our own logic rather than relying on external authority. This is obvious but not easy to practice in reality, and Lee Il-min directly shows how to implement this obvious principle. This lecture was a valuable experience that didn't just teach technology but also conveyed the mindset and attitude that developers should have. I highly recommend it to those who want to approach development seriously.