Provide security architecture guidance for sensitive systems, including identity and access management, logging and monitoring, endpoint protection, vulnerability management, network segmentation, secure cloud design, data handling, and secure software development practices. Experience operating in regulated environments subject to NIST SP 800-171, CMMC, DFARS, NIST SP 800-53, FedRAMP, ISO 27001, SOC 2, CUI handling, ITAR, export control, aerospace, defense, or other government-driven security requirements.