During January 2025, Dahua enhanced retry tracking and job introspection for concurrent RPC execution in the google/langfun repository. Using Python and leveraging asynchronous programming and concurrency, Dahua refactored the retry logic by introducing a RetryEntry structure and integrating retry statistics with LMSamplingUsage. The work extended the Job-based APIs so that concurrent_execute and concurrent_map now return Job objects, improving observability and debugging capabilities. Instrumentation was added to quantify the time impact of retried RPC calls, enabling more accurate cost and performance analysis. This feature-focused effort improved reliability and developer productivity through better API ergonomics and enhanced error handling.