How do you manage dependency injection in a large Flutter app?

By utilizing Service Locators (get_it) combined with Dependency Injection frameworks (injectable), or utilizing Riverpod.

For highly scalable architectures, manually passing repositories down constructors is unmaintainable. Tools like get_it act as a global service locator, holding Singletons and Factory instances of your classes. The injectable package uses code generation to automatically wire up dependencies based on annotations.