Mainframe Engineer

Description
We are seeking an IBM Mainframe Full Stack Systems Engineer experienced with end to end engineering and modernization of large scale enterprise IBM Z environments. This role requires deep, hands on expertise across multiple z/OS versions, core subsystems, security platforms, storage, networking, virtualization, and performance management in highly regulated, mission critical environments.
This role is engineering first, focused on architecture, deep technical analysis, system tuning, and modernization readiness. The engineer will play a critical role in proofing the mainframe platform, ensuring technical compatibility, stability, and performance as the stack evolves.
Core Responsibilities
z/OS Platform Modernization & Upgrade Engineering
Engineer for multiple concurrent legacy and current z/OS versions including Version interoperability, Incremental upgrade paths, Dependency validation across the stack, Pre upgrade technical assessments, Post upgrade stabilization, and tuning
Full Stack Mainframe Engineering (Subsystem Depth) - Provide deep system level engineering expertise across the core IBM Z stack i.e. but not limited to:
DB2 for z/OS - Subsystem configuration, performance characteristics, and version interactions
CICS TS - System level behavior, workload tuning, and modernization readiness, TLS enablement impacts
IMS (DB/DC) - Platform interaction, efficient tuning, and coexistence with modern stacks
IBM MQ for z/OS - Queue Manager architecture and configuration, MQ subsystem behavior across z/OS and middleware upgrades, Performance tuning (buffer pools, logging behavior, workload patterns), Dependency analysis with CICS, DB2 for z/OS, IMS, and distributed platforms. TLS enabled channel architecture and modernization
Common enterprise schedulers (e.g., CA-7, Control-M) and other ISV tooling
Compiler and language versions and when recompilations are necessary during upgrades
Common mainframe integrations, including Change Data Capture (CDC) tools, Extract, Transform, and Load (ETL) tools, and DB2 Gateway
Mainframe terminal emulators
Maintain a holistic view of cross subsystem dependencies during upgrades
Storage, Networking & Virtualization Engineering, providing engineering insight into:
Mainframe storage behavior, layout, and recovery implications during modernization
Mainframe networking, including SNA, VTAM, and TCP/IP interactions
Design around z/VM and virtualized environments
Identify infrastructure constraints that limit modernization or performance gains
Security Engineering
Review and engineer as needed for RACF and ACF2 security platforms to maintain access controls, profiles, auditing, logging, and compliance enforcement
Partner as needed with risk, audit, and application teams to review and ensure policy alignment and regulatory compliance
Mainframe security best practices, including encrypting data in transit
Leverage SMF, RMF, and operational metrics to analyze system performance, Identify bottlenecks, support capacity planning, and forecasting
Review and recommend tuning system parameters and subsystem configurations to optimize throughput, response time, and cost efficiency
Help identify trends and risks impacting availability or scalability
Review and recommend operational tasks automation opportunities using REXX, CLIST, JCL, TSO/ISPF, reducing manual effort through automation, standardization, and self healing processes
Collaboration & Leadership - Partner with Application teams, Middleware teams, Security & risk organizations, and Vendors (IBM and ISVs)
Job Type & Location
This is a Contract position based out of Chicago, IL.
Pay and Benefits
The pay range for this position is $10.00 - $70.00/hr.
Eligibility requirements apply to some benefits and may depend on your job classification and length of employment. Benefits are subject to change and may be subject to specific elections, plan, or program terms. If eligible, the benefits available for this temporary role may include the following: • Medical, dental & vision • Critical Illness, Accident, and Hospital • 401(k) Retirement Plan - Pre-tax and Roth post-tax contributions available • Life Insurance (Voluntary Life & AD&D for the employee and dependents) • Short and long-term disability • Health Spending Account (HSA) • Transportation benefits • Employee Assistance Program • Time Off/Leave (PTO, Vacation or Sick Leave)
Workplace Type
This is a fully remote position.
Application Deadline
This position is anticipated to close on Jul 24, 2026.

About TEKsystems


We're partners in transformation. We help clients activate ideas and solutions to take advantage of a new world of opportunity. We are a team of 80,000 strong, working with over 6,000 clients, including 80% of the Fortune 500, across North America, Europe and Asia. As an industry leader in Full-Stack Technology Services, Talent Services, and real-world application, we work with progressive leaders to drive change. That's the power of true partnership. TEKsystems is an Allegis Group company.


The company is an equal opportunity employer and will consider all applications without regards to race, sex, age, color, religion, national origin, veteran status, disability, sexual orientation, gender identity, genetic information or any characteristic protected by law.

About TEKsystems and TEKsystems Global Services


We're a leading provider of business and technology services. We accelerate business transformation for our customers. Our expertise in strategy, design, execution and operations unlocks business value through a range of solutions. We're a team of 80,000 strong, working with over 6,000 customers, including 80% of the Fortune 500 across North America, Europe and Asia, who partner with us for our scale, full-stack capabilities and speed. We're strategic thinkers, hands-on collaborators, helping customers capitalize on change and master the momentum of technology. We're building tomorrow by delivering business outcomes and making positive impacts in our global communities. TEKsystems and TEKsystems Global Services are Allegis Group companies. Learn more at TEKsystems.com.


The company is an equal opportunity employer and will consider all applications without regard to race, sex, age, color, religion, national origin, veteran status, disability, sexual orientation, gender identity, genetic information or any characteristic protected by law.


San Francisco Fair Chance Ordinance: Pursuant to the San Francisco Fair Chance Ordinance, for all positions located in the city and county of San Francisco, we will consider for employment qualified applicants with arrest and conviction records.


Massachusetts Lie Detector: It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.


Use of Artificial Intelligence (AI): We may use Artificial Intelligence (AI) to support parts of our hiring process, including sourcing, screening, and evaluating candidates. AI helps assess applications and qualifications, but final decisions are made by our hiring team. By applying, you acknowledge and agree that your application may be reviewed using AI tools.