Worked on the nestjs/nest repository to enhance dependency injection reliability by implementing a safety mechanism for dependency resolution. Addressed a core issue where get() could inadvertently instantiate non-static or implicitly request-scoped dependency trees, introducing an explicit error path and guiding developers to use resolve() for such cases. Developed targeted tests within NestApplicationContext specs to validate the new behavior, ensuring robust handling of complex DI graphs. Utilized TypeScript and backend development skills to improve clarity and maintainability in dependency management, reducing runtime errors and aligning with long-term stability goals. Focused on test-driven validation and traceable, production-ready code changes.