Worked on enhancing the aws/s2n-quic repository by implementing handshake cancellation and explicit error handling for application data generation. Focused on updating the make_application_data callback to return a Result, which allowed for early termination of handshakes and clearer error propagation when data generation failed. Leveraged the path_secrets_ready callback to cancel handshakes when preconditions were unmet, reducing unnecessary cryptographic operations and improving overall reliability. This work demonstrated a callback-driven API design and Result-based error signaling, aligning with best practices for end-to-end handshake lifecycle control. Utilized Rust and applied expertise in cryptography and network programming throughout the development process.