Eli Grubb focused on backend engineering within the bitwarden/server and bitwarden/sdk-internal repositories, addressing cryptographic maintainability and reliability. Over three months, Eli refactored encryption feature flags in C# to streamline the server codebase, reducing technical debt and aligning with evolving encryption strategies. In Rust, Eli enhanced sdk-internal by implementing a backward-compatible fix for UserKeyState initialization, improving stability for legacy clients. Additionally, Eli resolved a cipher key rotation bug, ensuring correct key unwrapping and secure key management during cryptographic operations. The work demonstrated depth in backend development and cryptography, emphasizing code hygiene, traceability, and risk mitigation across complex security-sensitive workflows.