Mainframe Developer

We are seeking an experienced Mainframe Developer to design, develop, enhance, and support critical batch and online applications running on our z/OS mainframe platform. This role will support core business systems while also contributing to ongoing application modernization and technology transformation initiatives.

The ideal candidate brings strong hands-on experience with COBOL and JCL, along with working knowledge of PL/I, Easytrieve, DB2, VSAM, and mainframe development tools. This individual will work across the full software development lifecycle, partnering with business analysts, QA engineers, operations teams, and other developers to deliver reliable, scalable, and maintainable mainframe solutions.

The role requires a combination of strong development skills, production troubleshooting capabilities, attention to detail, and the ability to work effectively within a collaborative delivery environment.

Key Responsibilities

Mainframe Application Development

• Design, develop, enhance, and maintain COBOL-based applications
• Develop and support programs using PL/I and Easytrieve
• Build and maintain batch and online mainframe applications
• Translate functional and technical requirements into application solutions
• Develop reusable, maintainable, and well-documented code
• Perform unit testing and support integration and system testing

JCL & Batch Processing

• Develop, modify, and troubleshoot JCL
• Support batch job scheduling and execution
• Analyze job failures, abends, and processing exceptions
• Troubleshoot dependencies and batch-processing issues
• Support restart, recovery, and production processing procedures
• Identify opportunities to improve batch reliability and performance

Database & File Processing

• Develop applications interacting with DB2
• Work with VSAM datasets and file structures
• Develop and maintain data-access and file-processing routines
• Troubleshoot database and data-related application issues
• Support data validation, reconciliation, and testing activities

Source Code & Release Management

• Manage source code and application changes using ChangeMan
• Support code promotion across development, test, and production environments
• Follow established version-control and release-management processes
• Prepare implementation and deployment documentation
• Coordinate application releases with QA and operations teams
• Maintain appropriate change and deployment records

Production Support & Troubleshooting

• Analyze and resolve production application issues
• Diagnose abends, data issues, batch failures, and performance bottlenecks
• Perform root-cause analysis for recurring incidents
• Develop and implement corrective solutions
• Support production deployments and post-release validation
• Partner with operations and support teams during incident resolution

Testing & Quality

• Develop unit test cases and validate application changes
• Support functional, integration, regression, and user acceptance testing
• Troubleshoot defects identified during testing
• Validate data and application processing results
• Participate in code reviews and technical quality reviews
• Ensure solutions meet established development and documentation standards

Cross-Functional Collaboration

• Partner with business analysts to understand requirements and business processes
• Collaborate with QA teams on testing strategies and defect resolution
• Coordinate with production operations on deployments and support
• Participate in technical design and solution discussions
• Communicate risks, dependencies, issues, and implementation considerations
• Maintain clear technical and operational documentation

Mainframe Modernization

• Support modernization of existing mainframe applications where appropriate
• Analyze legacy applications, dependencies, interfaces, and business logic
• Assist with code migration and application transformation initiatives
• Document existing systems to support modernization planning
• Collaborate with architecture and engineering teams on modernization approaches
• Help maintain business continuity while legacy capabilities are modernized

Required Qualifications

• 4+ years of hands-on mainframe application development experience
• Strong development experience with COBOL
• Strong experience developing and troubleshooting JCL
• Working knowledge of PL/I
• Working knowledge of Easytrieve
• Experience with ChangeMan or comparable mainframe change-management tools
• Experience working with DB2
• Familiarity with VSAM
• Hands-on experience with TSO/ISPF
• Experience developing and supporting batch-processing applications
• Strong production debugging and troubleshooting capabilities
• Experience diagnosing application abends and job failures
• Understanding of mainframe application development lifecycle and release processes
• Strong technical documentation skills
• Strong analytical and problem-solving abilities
• Effective written and verbal communication skills
• Ability to work collaboratively across development, QA, business, and operations teams

Preferred Qualifications

• Experience with CICS
• Experience with IMS
• Experience with IBM MQ
• Experience with File-AID
• Experience with Endevor
• Experience with Control-M
• Mainframe application performance tuning experience
• Experience with mainframe modernization initiatives
• Experience with legacy code analysis and remediation
• Exposure to mainframe-to-cloud or distributed-platform migration initiatives
• Experience working within Agile or iterative delivery environments

Technical Skills

Languages: COBOL, PL/I, Easytrieve
Batch: JCL
Database/Data: DB2, VSAM
Platform: IBM z/OS
Development Environment: TSO/ISPF
Change Management: ChangeMan
Preferred Technologies: CICS, IMS, MQ
Preferred Tools: File-AID, Endevor, Control-M

Key Competencies

• Mainframe application development
• Batch processing and troubleshooting
• Production support
• Root-cause analysis
• Legacy application analysis
• Application modernization
• Software quality and testing
• Technical documentation
• Problem solving
• Cross-functional collaboration
• Attention to detail
• Ownership and accountability

What Success Looks Like

The successful Mainframe Developer will be able to quickly understand existing mainframe applications and business processes, independently develop and troubleshoot COBOL and JCL solutions, reliably support production systems, and collaborate effectively with business and technology teams.

Beyond maintaining existing systems, this individual will help ensure that critical mainframe applications remain stable, maintainable, and well understood while the organization advances its broader modernization efforts.