Charles Seille enhanced error messaging for swap providers in the LedgerHQ/ledger-live repository, focusing on improving clarity and maintainability within the swap feature. He standardized error messages by replacing provider-specific terminology with generic language, using JSON to update messaging logic and ensure consistency across different providers. This approach reduced ambiguity for users and streamlined the onboarding process for future providers, supporting both internationalization and localization requirements. Charles aligned code changes with documentation and product goals, demonstrating attention to detail in error handling and user experience. The work addressed a targeted need, delivering a focused feature update within a one-month period.