Worked on the google/langextract repository to deliver a robust JSON serializer for handling complex cache key objects, specifically dataclass and enum types, within the GCSBatchCache component. The solution involved integrating the serializer into the cache’s hash computation and write path, ensuring deterministic hashing and preventing crashes caused by unsupported key types. Regression tests were added to validate consistent behavior for these complex objects, improving cache reliability across batch jobs. The codebase was refactored to reuse the new serializer, reducing duplication and simplifying maintenance. Python was used throughout, with a focus on backend development, data serialization, and unit testing.