Job#: 3025461 Job Description: Role: Sr Mainframe Engineer
Duration: Multi-year contract
Location: Hybrid - 4 days/week onsite in SE MI
Description:The Senior Mainframe Engineer is responsible for designing, developing, testing, deploying, and maintaining software applications that meet business and customer needs. This role participates in the full software development lifecycle and serves as a technical leader for large-scale mainframe applications, supporting both online and batch workloads.
The position requires deep mainframe expertise, strong problem-solving skills, and the ability to translate business requirements into stable, secure, and high-performing solutions.
Key ResponsibilitiesSoftware Development & Architecture- Design, develop, test, deploy, and maintain software applications across the full development lifecycle.
- Assess application requirements and determine appropriate technology stacks, integration methods, and deployment strategies.
- Create high-level software architecture designs that define system structure, components, and interfaces.
- Develop and maintain back-end components including APIs, microservices, and batch processes.
- Create user-friendly and intuitive interfaces where applicable.
Customer & Stakeholder Engagement- Engage with customers and stakeholders to understand use cases, pain points, and functional requirements.
- Advocate for user-centric, scalable, and maintainable software solutions.
- Collaborate closely with cross-functional teams including product owners, designers, architects, and infrastructure teams.
Quality, Testing & Performance- Define and implement software testing strategies, standards, and processes aligned with organizational goals and industry best practices.
- Drive test data management activities including data propagation, masking, and execution of end-to-end test cycles.
- Proactively monitor system stability and performance, identifying and resolving errors and bottlenecks.
- Continuously improve application performance and development efficiency through optimization and adoption of new technologies.
Operational Support & Production Stability- Provide 24/7 production support for critical mainframe applications, including off-hours and weekend coverage.
- Manage and resolve production incidents with strong root cause analysis and incident reporting.
- Oversee daily operational tasks to ensure workloads are completed accurately, timely, and in accordance with procedures.
- Manage software configurations using tools such as Endeavor and GitHub.
Security, Compliance & Governance- Support and enforce security best practices to safeguard sensitive data, including encryption and anonymization.
- Ensure secure handling of PII and confidential company information.
- Maintain system security credentials including passwords, client IDs/secrets, and certificates.
- Ensure procedural compliance to support successful internal (e.g., GAO) and external regulatory audits.
Technical Leadership- Lead technical discussions, anticipate dependencies, and evaluate tradeoffs for complex initiatives.
- Accurately size and estimate technical work.
- Mentor and guide team members as a senior technical resource.
- Translate business requirements into fully tested, production-ready software solutions.
- Evaluate and incorporate emerging technologies and participate in evolving platform strategies.
Required Skills & Technologies- Mainframe Technologies: COBOL, JCL, TSO/ISPF, VSAM, CICS, DB2, CA-7, z/OS
- Development & Integration: REST APIs, JSON, Batch Processing
- Testing & Quality: Software Testing, Performance Testing, Application Testing, Root Cause Analysis
- Tools: IBM DB2, CA-7, TSO/ISPF
- Nice to have: IBM Debug, File Manager, Fault Analyzer, Endeavor
- Practices: Test-Driven Development (TDD), Continuous Integration (CI), Continuous Delivery (CD)
- Support & Analysis: Application Support, Program Analysis, Requirements Analysis
Experience Requirements- 10+ years of hands-on experience in mainframe development and support
- 8+ years of software development experience
- Proven experience supporting both online and batch mainframe applications
- Demonstrated experience managing production systems in a 24/7 operational environment
Preferred Skills- Process Improvement
- Data Management
Education- Required: Bachelor's Degree
- Preferred: Additional safety training, licensing, or certifications (if applicable)
EEO Employer
Apex Systems is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law. If you have visited our website in search of information on employment opportunities or to apply for a position, and you require an accommodation in using our website for a search or application, please contact our Employee Services Department at or .
Apex Systems is a world-class IT services company that serves thousands of clients across the globe. When you join Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing in Talent Satisfaction in the United States and Great Place to Work in the United Kingdom and Mexico. Apex uses a virtual recruiter as part of the application process. Click for more details.
Apex Benefits Overview: Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our 'Welcome Packet' as well, which an Apex team member can provide.
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