Job ID# 10TEK0852-031826 – Posted 03/18/2026 – Downey, CA

We are seeking an experienced Senior Systems Programmer – Legacy Systems to support, maintain, and enhance enterprise z/OS mainframe environments. This role is responsible for both ongoing system maintenance and the development of operating system environments, ensuring optimal performance, security, and reliability.

The ideal candidate will bring deep expertise in mainframe technologies, strong leadership experience, and the ability to manage complex system upgrades and integrations with minimal downtime.

System Maintenance & Support

• Plan and execute system upgrades in alignment with company-established schedules

• Monitor and verify the health and performance of all z/OS systems

• Analyze issues reported by development teams and provide recommendations and resolutions

• Ensure compatibility between software applications and operating systems

• Perform timely hardware upgrades with minimal disruption to operations

• Apply patches and updates to security and system software regularly

• Collaborate with stakeholders to test applications following system upgrades

Systems Development & Engineering

• Analyze system requirements, risks, and cost considerations

• Evaluate, select, and validate system software environments

• Install and configure compilers, assemblers, and system utilities

• Integrate hardware and software components across system environments

• Monitor, fine-tune, and optimize system performance

• Evaluate emerging technologies and assess their impact on the environment

• Ensure security and information assurance policies are implemented and maintained

• Strong expertise in IBM mainframe technologies, including:

  • z/OS, IMS, DB2, ADABAS

  • SMP/E, JCL, IMS DB/DC, CICS

  • ACF2 security, VTAM, TCP/IP, NetView

  • Control-M, CA Spool

  • Natural/SuperNatural, EntireX

  • IMS & DB2 BMC Tools

  • HMC, HOD, IODF, VTS

• Proficiency in programming and scripting:

  • Assembler, COBOL, REXX

• Strong knowledge of system architecture, performance tuning, and capacity planning

• Excellent troubleshooting and analytical skills

• Ability to lead complex infrastructure initiatives and mentor junior staff

• z/OS, HCD, z/OSMF

• IBM z16 and z17 hardware platforms

• CA ACF2 V17

• Host On-Demand (HOD) V16.1

• Minimum 7 years of experience in z/OS systems programming

• At least 4 years in a lead or senior role managing complex mainframe environments

Bachelor’s degree in Information Technology, Computer Science, Engineering, or a related field

• This is a systems programming role (not a development role)—mainframe developer resumes will not be considered

• Candidate must have extensive hands-on experience with mainframe hardware and system software

• Initial three (3) weeks onsite required

• Ongoing onsite presence required for major system upgrades