Role : RACF z/OS Security Expert Location : Frisco, TX (Onsite) RACF z/OS Security Expert to manage and maintain security infrastructure across our mainframe environment, with emphasis on security administration and certificate lifecycle management. Key Responsibilities RACF Security Administration Design, implement, and maintain RACF security policies and user access controls Manage user IDs, groups, and resource profiles (datasets, transactions, programs) Conduct security audits, access review