Worked on the gchq/CyberChef repository to address a critical issue in the BLAKE3 hashing functionality, where large input data produced incorrect all-zeros outputs. Tackled this by replacing the existing hashing library with a more reliable implementation and developing comprehensive tests to cover edge cases, including large payloads and keyed hashing scenarios. Focused on improving data integrity and reliability in cryptographic operations, the work leveraged JavaScript and cryptography expertise, with an emphasis on robust testing practices. These changes enhanced the reliability of hashing-related data processing and increased test coverage, reducing the risk of future regressions in the codebase.