For the past four months, I have been exploring the Spring ecosystem, learning about architectures, design patterns, and how large Java backend systems are structured. Among the many technologies in the ecosystem, one just sat in the backdrop silently making my life easier. I already knew what Spring Boot did at a high level. It handles auto-configuration, embedded servers, starter dependencies, and opinionated defaults. But, I never truly appreciated why those features mattered. So I decided to build a Spring MVC application without using Spring Boot. The goal was simple: create a simple API. What I ended up learning was far more valuable than the API itself. The first thing I discovered was that Spring applications can actually have two separate configurations: Root Application Context Web Application Context The Root Application Context contains beans shared across the entire application, such as services, repositories, data sources, and infrastructure-related beans.…