Mainframe Security Architect - z/OS | RACF | ACF2 (Remote or London)

Mainframe Security Architect – z/OS | RACF | ACF2

Were seeking an experienced Mainframe Security Architect to join an enterprise infrastructure team, with a focus on safeguarding their IBM Z Series environments.

You will be at the forefront of mainframe security strategy, designing and implementing robust access controls, monitoring systems, and risk management frameworks. This is a high-impact role with wide scope for technical authority and strategic influence across a complex, high-volume infrastructure.

Key Responsibilities:

• Architect and maintain end-to-end security frameworks for IBM Z Series mainframe environments.
• Lead threat modeling, vulnerability assessments, and remediation plans specific to z/OS, RACF, ACF2 or Top Secret environments.
• Collaborate with infrastructure, application, and compliance teams to implement secure configurations and access control models.
• Drive security policy enforcement across core systems including CICS, DB2, IMS, and MQ.
• Evaluate and integrate security tools (e.g. IBM zSecure, CA ACF2 utilities, encryption modules) into mainframe operations.

Experience:

• Proven experience as a security architect or engineer inz/OS or IBM Z Series environments.
• Strong command ofRACF,ACF2, orTop Secretmainframe security systems.
• Hands-on experience with enterprise-wide identity and access management (IAM) for mainframes.
• Expertise in encryption, data masking, and privileged access control on z/OS.
• Experience designing controls aligned withISO 27001,NIST, orGDPRcompliance.

Why Join?

• Be part of a mission-critical function supporting large-scale enterprise operations.
• Work in a collaborative, forward-thinking culture with a focus on innovation and resilience.
• Access to ongoing training, certifications, and leadership development.