Senior Systems Programmer – Legacy Systems

Hrimoveisararaquara; Downey (CA); On-site; USD 135,000 - 180,000; Full time

Job summary

Hrimoveisararaquara is seeking a Senior Systems Programmer - Legacy Systems to support, maintain, and enhance enterprise z/OS mainframe environments in Downey, CA. The role emphasizes system maintenance, upgrades, security, and reliability.

Ideal candidates will have deep mainframe expertise and proven leadership in managing complex upgrades and integrations with minimal downtime, ensuring smooth operations and high availability.

Qualifications

• 7+ years of hands-on z/OS systems programming experience.
• 4+ years in lead or senior roles managing complex mainframe environments.
• Bachelor’s degree in IT, Computer Science, Engineering or related field.

Responsibilities

• Maintain, support and enhance enterprise z/OS mainframe environments.
• Plan and execute system upgrades with minimal downtime.
• Monitor health and performance of all z/OS systems.
• Collaborate with stakeholders to test applications after upgrades.
• Lead infrastructure initiatives and mentor junior staff.
• Ensure security and information assurance policies are implemented.

Skills

z/OS

IMS

DB2

ADABAS

SMP/E

JCL

CICS

ACF2 security

VTAM

TCP/IP

NetView

CA Spool

Natural/SuperNatural

EntireX

HMC

HOD

IODF

VTS

Troubleshooting

Leadership

Education

Bachelor’s degree in IT/CS/Engineering

Tools

z/OS tools

CA Spool

HOD

NetView

Job description

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

Key Responsibilities

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

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

Required Skills:

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:

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

IBM z16 and z17 hardware platforms

CA ACF2 V17

Host On-Demand (HOD) V16.1

Experience Requirements

Minimum 7 years of experience in z/OS systems programming

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

Education:

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

Additional Information:

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