Marvin contributed to the chipsalliance/Caliptra and chipsalliance/caliptra-sw repositories by enhancing both documentation and cryptographic functionality. He improved documentation usability by fixing broken README links, ensuring accurate navigation to hardware specification documents and aligning references with the correct version tags. On the technical side, Marvin introduced flexible SHA input length handling in Rust, allowing the update_bytes function to accept an optional data length parameter and trim unused padding, which enabled precise hashing of partial data. He reinforced these changes with targeted unit tests, demonstrating a focus on reliability and maintainability in embedded systems and cryptography workflows across both projects.