Worked on security hardening for the Sovereign-Labs/sovereign-sdk repository, focusing on backend development and API security using Rust. Developed and integrated a feature that enforces maximum sizes for incoming transactions and WebSocket messages, introducing in-line checks and updating configuration constants to reject oversized data. This approach mitigated the risk of denial-of-service attacks by preventing resource exhaustion during periods of high load. Updated the test suite to ensure coverage of the new constraints and revised configuration files for clarity and maintainability. The work improved the reliability and scalability of the system, supporting safer client workload management and robust backend operations.