Worked on stabilizing the SSH proxy workflow in the yuwata/systemd repository by addressing a critical bug affecting connection reliability with AF_VSOCK multiplexers such as Firecracker and vhost-device-vsock. Applied expertise in C programming, network programming, and system programming to deliver a targeted fix that ensures the SSH proxy explicitly waits for and processes the OK PORT response from vsock multiplexers before handing over the socket file descriptor to the SSH client. This minimal, robust change prevents premature socket handover and reduces unintended SSH connection aborts, resulting in a more reliable and forward-compatible SSH proxy handshake for complex virtualized environments.