Senior Mainframe Security Engineer & Penetration Tester

Truist Bank; Florida; Hybrid; USD 140,000 - 180,000; Full time

Benefits offered by this job

Medical, dental, vision

401(k) plan

Paid time off

Bonus potential

Job summary

Truist Bank is seeking a senior penetration tester focused on mainframe environments to advance our offensive security program. You will perform advanced tests across z/OS components (RACF, ACF2/Top Secret, CICS, IMS, Db2, MQ) and related subsystems, using scripting (REXX, JCL, Assembler, Python) to uncover and remediate vulnerabilities.

The role requires deep cybersecurity knowledge, strong technical writing, and the ability to communicate findings to both technical and non-technical

Qualifications

• Bachelor’s degree or equivalent education, training, and work-related experience.
• Minimum of 7 years of experience in security engineering or related cybersecurity roles.
• Deep specialized knowledge in cybersecurity principles, theories, and concepts.
• Proven experience in software development lifecycle security practices.
• Deep knowledge of threat modeling, security testing, and penetration testing.
• Experience implementing and managing complex information security technologies.

Responsibilities

• Conducts black box, grey box and assumed breach penetration tests of enterprise z/OS environments, covering the USS (Unix System Services), external security managers (RACF, ACF2, Top Secret) subsystems, (CICS, IMS, db2, MQ) batch processing (JCL, JES2) TSO/ISPF, and network facing services (TN3270, FTP, Z/OS Connect and Rest APIs, NJE)
• Uses manual techniques custom scripting (REXX, JCL, Assembler, Python) and offensive tooling to enumerate users and resources, map datasets, access unprotected spool and job output, and exploit misconfigured CICS transactions, and insecure interfaces)
• Evaluates exploitability and business impact and applies sound judgment when determining finding severity and risk.
• Documents findings with clear reproduction steps, supporting evidence, impact statements, and practical remediation recommendations.
• Present and defends technical findings in discussions with application teams, mainframe engineers, technology leaders, risk partners, and other stakeholders.
• Performs validation and retesting to confirm remediation and risk reduction, and maintains testing evidence needed to support audit, regulatory, and compliance requirements (PCI DSS, SOX)
• Partners with internal and external testing teams to improve mainframe testing coverage, methodologies, playbooks, tooling, automation, and repeatable processes.
• Performs peer reviews of penetration testing reports and provides technical guidance and mentorship to other security professionals.
• Maintains current knowledge of mainframe attack techniques, security controls, platform changes, offensive security practices, and relevant industry threats.

Skills

Security engineering

Penetration testing

Threat modeling

Mainframe security

Documentation

Stakeholder communication

Education

Bachelor’s degree or equivalent

Tools

REXX

JCL

Assembler

Python

Job description

Truist Bank is seeking a senior penetration tester focused on mainframe environments to advance our offensive security program. You will perform advanced tests across z/OS components (RACF, ACF2/Top Secret, CICS, IMS, Db2, MQ) and related subsystems, using scripting (REXX, JCL, Assembler, Python) to uncover and remediate vulnerabilities.

The role requires deep cybersecurity knowledge, strong technical writing, and the ability to communicate findings to both technical and non-technical