Worked on the facebook/fbthrift repository to enhance the correctness and reliability of immutable Thrift Python Sets. Addressed a bug in the implementation of rich comparison operators, ensuring that greater-than and greater-than-or-equal-to semantics now align with Python’s set partial order. This adjustment reduces subtle ordering bugs for downstream Thrift clients. Developed and integrated comprehensive unit tests to validate subset and superset behaviors, thereby improving regression protection and overall test coverage for immutable collections. The work was carried out using Python and focused on software development best practices, with an emphasis on robust unit testing and maintainable code quality.