Dependency injection is a crucial technique in modern Android development, enabling programmers to deliver class dependencies without the classes obtaining them independently. This approach enhances app architecture by improving code reusability, refactoring ease, and testing. The article explores the two most popular dependency injection libraries for Modern Android Development (MAD): Dagger’s Hilt and Koin. Hilt, built on Dagger 2, simplifies implementation by generating setup code and is integrated into Android's ecosystem, offering compile-time dependency error checking. Koin, on the other hand, is a lightweight, Kotlin-based library that uses a Service Locator pattern and provides runtime dependency, making it more straightforward but potentially impacting runtime performance. The choice between these libraries depends on project needs, team expertise, and language preferences, with Hilt being more suitable for Java-based projects and complex DI requirements, while Koin aligns better with Kotlin-centric projects and ease of use.