Fabiana refactored error handling across the waku-org/nwaku repository by adopting idiomatic Result-based patterns in Nim. She replaced legacy isOk, isErr, and get usage with valueOr and the question mark operator, standardizing error propagation and reducing boilerplate throughout the codebase. This approach improved code readability and maintainability, making error paths more robust and easier to follow for both current and future contributors. Her work demonstrated strong skills in Nim programming, error handling, and refactoring, drawing on patterns familiar from Rust. The changes laid a foundation for safer module interactions and streamlined onboarding for new developers working with the repository.