📂 Paradigm 📝 AOP Nestjs의 Request lifecycle과 AOP 📝 OOP 객체지향프로그래밍이란? Single responsibility principle Open Closed Principle Liskov Substitution Principle Interface Segregation Principle Dependency Inversion Principle ETC 객내가 사용하는 DTO객체는 객제가 맞는가체지향프로그래밍이란?