An Nguyen developed a flexible DeleteCallback API for the univelop/yust_ui repository, focusing on enhancing API versatility within Flutter applications. By updating the callback type from Future<void> to FutureOr<void> and introducing an import for dart:async, An enabled the callback to support both synchronous and asynchronous results. This technical approach, implemented in Dart, reduced boilerplate and improved compatibility for downstream integrations, allowing developers to compose callbacks more easily. The work demonstrated a clear understanding of asynchronous programming patterns in Flutter and addressed the need for more adaptable API design, though it was limited in scope to a single feature update.