100% Remote - Urgently require - Mainframe Developer (COBOL / NaturalOne / Adabas) - Only W2.

We are seeking an experienced Mainframe Developer to enhance and support a mission-critical financial accounting platform running on IBM z/OS. The selected consultant will work on expanding existing core accounting functionality by implementing new pooled-account structures, modifying legacy applications, and ensuring accurate financial processing, reconciliation, and reporting.

This role requires strong expertise in Enterprise COBOL, Natural/NaturalOne, Adabas, VSAM, JCL, and financial systems operating in highly regulated environments. The ideal candidate should be comfortable analyzing large, complex legacy codebases and implementing enhancements with minimal supervision. Key Responsibilities

• Analyze existing account management, posting, and balance-maintenance programs.
• Design and develop new account-processing functionality within an existing mainframe system.
• Enhance COBOL programs, JCL jobs, and batch processes while maintaining system performance.
• Implement reconciliation, audit trail, exception reporting, and accounting controls.
• Create test data, unit tests, regression tests, and parallel-run validation comparisons.
• Support deployments, production rollouts, and post-implementation activities.
• Produce technical documentation, data-flow diagrams, and operational runbooks.

• 15+ years of Mainframe Background experience.
• 5+ years of Enterprise COBOL development experience in a z/OS environment.
• 5+ years of experience with NaturalOne.
• 3+ years of JCL development and production support experience.
• 3+ years of experience with financial/accounting systems involving:
• Double-entry posting
• Accrual and balance maintenance
• Reconciliation
• Month-end processing
• 3+ years of experience with Adabas and VSAM.
• Experience tracing and documenting undocumented legacy business logic through copybooks, call chains, and job streams.

Preferred Qualifications

• Experience with treasury systems, cash management, account pooling, or sweep processing.
• Knowledge of CA-7 scheduling and batch operations.
• Experience with REXX, Python, or Java.
• Exposure to z/OS Connect, IBM MQ, or REST-based integrations.
• Strong understanding of financial reconciliation and regulatory compliance processes.