During December 2025, Lie contributed to the fastapi/fastapi repository by implementing flexible dependency injection using functools.partial. This feature allows developers to partially apply dependencies, supporting both callable and generator dependencies within FastAPI applications. Lie approached the task with a focus on maintainability, reducing boilerplate and expanding options for dependency wiring in complex API designs. The implementation was thoroughly validated with comprehensive tests to ensure application integrity and correct behavior. Working primarily with Python and leveraging backend development and API development skills, Lie’s work enhanced the ergonomics of dependency injection, enabling more expressive and maintainable API architectures for the project.