Senior Mainframe Developer - ADABAS / Natural / COBOL

We are hiring a Senior Mainframe Developer to support a multi-phase engagement with a large New York City public-sector client. The work involves both keeping critical legacy mainframe applications running and supporting a modernization effort that includes data extraction, migration to SQL Server and Dynamics 365, and an eventual transition to a modern replacement platform.

This is a hands-on technical role. You will write code, troubleshoot production issues, build data extraction pipelines, and collaborate with internal teams, business stakeholders, and third-party consultants. You will participate in weekly status meetings, contribute to system analysis and design discussions, and own technical documentation for the components you touch.

The engagement is structured as a fixed-scope, milestone-based delivery over roughly nine months, with approximately 35 hours per week of expected effort. There is potential for a one-year extension based on performance and continued client need.

What You’ll Do:

• Maintain and administer existing mainframe applications, including monitoring, performance tuning, and incident resolution
• Extract data from mainframe applications using ADABAS, Natural, CICS, COBOL, VSAM, and flat files
• Use IBM utilities (IDCAMS, SORT, File Manager) to inspect and validate file contents
• Write and run JCL to compile and execute mainframe programs
• Develop in the TSO mainframe environment
• Transport extracted data from the mainframe to Windows servers using enterprise file transfer tools
• Load data into SQL Server and Dynamics 365 using SSIS, KingswaySoft, Visual Studio Integration Services, and Azure-based tooling
• Support the design and build of a data archive solution, including analysis, migration, and testing
• Troubleshoot production issues, perform root cause analysis, and implement corrective actions
• Participate in system analysis, design sessions, and requirements gathering
• Support the eventual transition from the legacy mainframe environment to a modern replacement system by partnering with internal teams, consultants, and end users
• Maintain clear, comprehensive technical documentation for all code, processes, data flows, and system changes
• Attend weekly status meetings to review progress, surface risks, and align on priorities

Do you have experience in Visual Studio?, * 10+ years of hands-on technical experience developing, maintaining, and customizing mainframe applications

• Strong, demonstrable expertise in:
• COBOL
• ADABAS
• Natural
• CICS
• VSAM
• JCL
• TSO mainframe development environment
• Experience with IBM mainframe utilities (IDCAMS, SORT, File Manager)
• Working knowledge of SQL Server and SQL Server Management Studio, including writing SQL queries
• Experience with SSIS (SQL Server Integration Services) for ETL workflows
• Excellent written and verbal communication skills - you will work directly with client stakeholders
• Authorized to work in the United States (W2 only - no C2C, no third-party agency submissions)

Preferred Qualifications:

• Experience with KingswaySoft SSIS components (or willingness to learn - straightforward for experienced SSIS developers)
• Experience loading data into Microsoft Dynamics 365 / CRM
• Familiarity with Microsoft Azure and Git
• Prior experience on NYC or NY State government IT engagements
• Experience with mainframe-to-modern-platform migration projects
• Experience designing or implementing data archive solutions, * Mainframe development: 10 years (Required)
• ADABAS: 5 years (Preferred)

$65 - $80 an hour - Contract, Engagement Logistics:

• Hours: Approximately 35 hours per week, structured around milestone deliverables
• Duration: 12 months, with mutual option to extend an additional 12 months

Pay: $65.00 - $80.00 per hour