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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Mainframe Software Engineer - **Company:** Apex Systems LLC - **Location:** Dearborn, MI, United States - **Experience:** Expert - **Salary:** $114,400.0 - $135,200.0 - **Contract:** Permanent contract - **Skills:** Testing (Software), Application Programming Interfaces (APIs), Agile Methodology, Artificial Intelligence, Applications Architecture, Software Applications, Application Performance Management, Batch Processing, BigQuery, Customer Information Control System (CICS), COBOL (Programming Language), Software Quality, Code Review, Continuous Delivery, Continuous Integration, Data Migration, IBM DB2, DevOps, Github, Job Control Language (JCL), Mainframes, Program Analysis, Secure Coding, Software Engineering, Software Systems, SQL Databases, Systems Integration, Strategies of Testing, Z/OS, Tso/ispf, Google Cloud, Performance Testing, Test-Driven Development (TDD), GitHub Copilot, Large Language Models, Prompt Engineering, Software Security, HybridCloud, Backend, Information Technology, Data Management, Cloud Migration, Restful APIs, Software Version Control, Programming Languages - **Published:** September 29, 2026 - **Apply:** https://jobs.mitalent.org/job-seeker/job-details/JobCode/411510183 ## About the Role * Bachelor's degree in Computer Science, Information Technology, Engineering, or a related field. * 10+ years of IT experience. * 8+ years of software development experience. * Strong proficiency in at least one programming language and practical experience with multiple development technologies. * Extensive experience with: + COBOL + DB2 + CICS + JCL + z/OS + TSO/ISPF + SQL + Batch Processing + REST APIs + GitHub * Experience with software testing, application support, program analysis, performance testing, and root cause analysis. * Strong understanding of Agile software development methodologies. * Experience using AI-assisted development tools and practices, including: + GitHub Copilot + AI-Assisted Development + Prompt Engineering + LLM API Integration + AI Code Review Preferred Qualifications * Experience with process improvement initiatives. * Familiarity with Google Cloud Platform (GCP). * Experience with: + BigQuery + Data Migration + Data Management * Exposure to cloud modernization and hybrid cloud environments. Desired Attributes * Strong analytical and problem-solving skills. * Excellent communication and stakeholder management abilities. * Ability to work independently and mentor junior team members. * Demonstrated commitment to continuous learning and adoption of emerging technologies. * Customer-focused mindset with a passion for delivering high-quality software solutions. ## Description We are seeking a Senior Mainframe Software Engineer to design, develop, test, maintain, and support enterprise software applications serving critical business functions. This role will be responsible for the full software development lifecycle, including architecture, development, testing, deployment, optimization, and production support. The ideal candidate will have extensive experience in Mainframe development (COBOL, DB2, CICS, JCL, z/OS) while also embracing modern development practices, APIs, Agile methodologies, DevOps principles, and AI-assisted development tools. Key Responsibilities * Partner with business stakeholders and customers to understand requirements, analyze use cases, and deliver user-centric solutions. * Design, develop, test, deploy, and maintain high-quality software applications and services. * Evaluate business and technical requirements to determine the appropriate architecture, technology stack, integration approach, and deployment strategy. * Create and maintain high-level and detailed application architecture designs. * Develop, enhance, and support mainframe applications using COBOL, DB2, CICS, JCL, TSO/ISPF, and z/OS technologies. * Design, develop, and maintain APIs, integrations, and backend services. * Collaborate with Product Owners, Architects, Designers, QA teams, and cross-functional stakeholders throughout the development lifecycle. * Define and implement testing strategies, standards, and best practices, including functional, integration, and performance testing. * Perform root cause analysis, troubleshooting, and production support activities. * Continuously improve application performance, reliability, maintainability, and scalability. * Utilize modern engineering practices such as: + Agile development + Test-Driven Development (TDD) + Continuous Integration/Continuous Delivery (CI/CD) + Version control and code review processes * Support application security practices, including data protection, encryption, and secure coding standards. * Leverage AI-assisted development tools (GitHub Copilot, OpenCode, and other LLM-based assistants) to accelerate development, improve code quality, and enhance productivity. * Evaluate emerging technologies and recommend solutions that improve engineering effectiveness and business outcomes. ## Related Videos - [Unlocking the Power of the Mainframe: Developing modern applications on z/OS](https://www.wearedevelopers.com/videos/764-unlocking-the-power-of-the-mainframe-developing-modern-applications-on-z-os) - [Shifting Stress to Progress— Understanding DevOps to do DevOps Better](https://www.wearedevelopers.com/videos/268-shifting-stress-to-progress-understanding-devops-to-do-devops-better) - [Innovating Developer Tools with AI: Insights from GitHub Next](https://www.wearedevelopers.com/videos/1268-innovating-developer-tools-with-ai-insights-from-github-next) - [Building with IBM Bob](https://www.wearedevelopers.com/videos/100275-building-with-ibm-bob) - [Bringing AI Model Testing and Prompt Management to Your Codebase with GitHub Models](https://www.wearedevelopers.com/videos/1536-bringing-ai-model-testing-and-prompt-management-to-your-codebase-with-github-models) - [Can This Elephant Dance? IBM Bob and the Future of AI-First Software Development](https://www.wearedevelopers.com/videos/100256-can-this-elephant-dance-ibm-bob-and-the-future-of-ai-first-software-development) ## Related Articles - [How We Built a Worry-Free System That Runs for 10+ Years – And What We’d Do Again](https://www.wearedevelopers.com/magazine/751-how-we-built-a-worry-free-system-that-runs-for-10-years-and-what-we-d-do-again) - [What’s the Difference between a Junior, Mid, and Senior Developer?](https://www.wearedevelopers.com/magazine/238-what-s-the-difference-between-a-junior-mid-and-senior-developer) - [Highest Paying Tech Companies for Developers](https://www.wearedevelopers.com/magazine/220-highest-paying-tech-companies-for-developers) - [7 Important Tips That Every Software Developer Should Know](https://www.wearedevelopers.com/magazine/101-7-important-tips-that-every-software-developer-should-know) - [Is Software Engineering Over-Saturated?](https://www.wearedevelopers.com/magazine/418-is-software-engineering-over-saturated) - [How Much FAANG Companies Actually Pay Software Engineers in 2025](https://www.wearedevelopers.com/magazine/230-how-much-faang-companies-actually-pay-software-engineers-in-2025)