It's fun to work in a company where people truly BELIEVE in what they're doing! Job Description Summary: Rocket Software is seeking a Mainframe Engineer to join the zAssure Security Portfolio team. This role focuses on deep system-level engineering, security analysis, and advanced diagnostics within z/OS environments. This is a highly specialized role requiring strong expertise in z/OS internals, HLASM (Assembler), and system-level debugging. The role combines product engineering with complex troubleshooting and customer-facing escalation support, making it critical to the success of our security solutions. The ideal candidate brings hands-on experience working with low-level system constructs, the ability to diagnose complex production issues, and a strong ownership mindset. Key Responsibilities Design, develop, and maintain HLASM-based components for z/OS security and system tooling (VAP and related products) Diagnose complex issues using z/OS diagnostic tools (including GTF traces) Analyze APF-authorized programs, SVCs, PC routines, and system behavior Perform deep root cause analysis for performance, system failures, and security exposures Work with JCL, ISPF, SDSF, and system utilities to debug and validate behavior Collaborate with engineering and support teams on L3 escalations and product fixes Contribute to tooling, automation, and modernization efforts Apply modern development practices (Git, AI-assisted debugging/workflows) Required Qualifications Minimum 10 years of experience in z/OS environments Strong expertise in: HLASM (Assembler) z/OS internals (mandatory) Hands-on experience with: JCL, ISPF, SDSF Batch job debugging and system diagnostics Proven experience in: Collecting and analyzing GTF traces (required) Debugging low-level system issues Strong understanding of: APF authorization, SVC, PC, memory and execution model z/OS security concepts (RACF awareness) Experience with Git or modern version control Strong problem-solving, debugging, and analytical skills Highly Desirable REXX scripting experience Knowledge of: System exits, hooks, and intercepts Performance tuning and advanced diagnostics Exposure to: DB2, VSAM, or system-level data structures Experience supporting customer escalations / L3 roles Work Model Collaborate with global (US-based) teams Flexibility for overlapping time zones when required Operate with high ownership and minimal supervision . Rocket Software Inc. is committed to creating a diverse environment and is proud to be an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. Rocket Software Inc. is also committed to compliance with all fair employment practices regarding citizenship and immigration status. At Rocket Software, we believe AI is a critical enabler of innovation and productivity. All Rocketeers are expected to actively leverage AI-powered tools and technologies, where appropriate, to enhance efficiency, improve decision-making, and deliver greater impact in their roles. Embracing continuous learning and the responsible use of AI is an essential part of how we work. As part of our commitment to a safe and trustworthy workplace, we include background and reference checks in our hiring process. Rocket is committed to working with and providing reasonable accommodation to individuals with physical and mental disabilities. If you need special assistance or an accommodation while seeking employment, please call: 781-577-4321 or send an email to people@rocketsoftware.com. We will make a determination on your request for reasonable accommodation on a case-by-case basis. If you like wild growth and working with happy, enthusiastic over-achievers, you'll enjoy your career with us! Companies around the world trust Rocket to solve their most complex business challenges by powering their critical infrastructure, business processes, and data. We help extend the value of these assets, enabling our customers to embrace the potential of cloud and mobile computing, advanced analytics, and the innovations of tomorrow. From the clothes we wear to the cars we drive, Rocket solutions power the back-end systems that thousands of brands rely on every day. At Rocket, software is about more than just code—it’s about people. We are passionate problem-solvers, working to make a difference for others. Our foundation is built on empathy, humanity, trust, and love, and we strive to embody these core values in everything we do. Whether we’re serving our customers, partners, or fellow Rocketeers, we are committed to treating everyone with the respect and care they deserve. Founded in 1990, Rocket Software is headquartered in Waltham, Massachusetts, and has 20 offices worldwide, bringing people and technology together to build a better future.

Software Engineer III (Mainframe Assembler(HLASM)- z/OS Security & Systems (zAssure Portfolio).

more at Rocket.

Principal Customer Solutions Engineer

Principal Customer Solutions Engineer

Software Engineer III

similar roles.

CISO / Head of IT Security - Fulltime Hybrid

Retail Security Systems Technician

Security Installer

Director, Senior Security Architect

Invoicing Coordinator

Entry Door Technicians and Installers