Worked on the Effect-TS repository family to enhance backend reliability and developer experience. Focused on improving error handling in database migrations by introducing a cause property to MigrationError, enabling clearer context and faster debugging when failures occur. Expanded and clarified developer documentation for the Duration.format function in the Effect-TS/website repository, providing practical examples and expected outputs to support both users and contributors. Coordinated updates across repositories to ensure consistent error semantics and documentation standards. Utilized TypeScript for backend changes and Markdown for technical writing, emphasizing maintainability, clear commit practices, and alignment between code improvements and user-facing documentation.