Jingjin Zhou refactored error handling in the awslabs/mcp repository, focusing on the AWS API MCP server. Using Python and backend development skills, Jingjin transitioned the error flow from returning error response objects to raising exceptions directly within the server. This approach clarified error propagation, improved debuggability, and brought the codebase in line with standard Python exception management practices. The refactor enhanced the maintainability and resilience of the API surface by enabling clearer stack traces and simplifying future updates. Jingjin’s work addressed error handling challenges and contributed to a more robust and observable backend service, though it did not involve bug fixes.