Administers and secures enterprise network, server, virtualization, backup, application, and Active Directory infrastructure. Configures and troubleshoots systems, routers, switches, firewalls, applications, HL7 interfaces, and SSL/TLS certificates. Leads infrastructure changes, security mitigation, asset lifecycle management, and backup testing. Provides Level III support, technical guidance, staff training, and mentorship while maintaining compliance with HIPAA, NIST, and PCI DSS requirements.