Define OT network architecture and configure cybersecurity controls in accordance with IEC 62443 or NIST SP 800-82, including zone and conduit design, VLAN and switch configuration, role-based access control, authentication, secure protocol configuration, and coordination of patching and application allow-listing. Prepare and execute software FAT, SAT, and commissioning test plans; maintain engineering documentation including functional specifications, control narratives, cause-and-effect matrices, tag lists, alarm databases, and as-built software records.