Worked on the upstash/workflow-js repository to enhance the Serve API by implementing a robust onError callback, allowing users to define custom error handling logic. The solution introduced a default error handler that leverages console.error and is encapsulated within a try-catch block, ensuring that failures within user-defined error handlers do not propagate and cause cascading issues. This approach improved the reliability and observability of the serving process, aligning with established error management patterns. The work focused on backend and API development using TypeScript, with particular attention to error handling strategies that strengthen the resilience and debuggability of the system.