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# Mainframe Developer

- **Company:** TDI LLC
- **Location:** United States (Remote available)
- **Experience:** Experienced
- **Salary:** $104,000.0
- **Contract:** Contract
- **Skills:** Java (Programming Language), Accounting Systems, Adaptable Database Systems, CLIST, COBOL (Programming Language), Software Debugging, Data Flow Control, Job Control Language (JCL), IBM WebSphere MQ, Rexx (Programming Language), Systems Analysis, Python (Programming Language), Mainframes, Performance Tuning, Regression Testing, Test Data, Virtual Storage Access Methods, Z/OS, Data Processing, Tso/ispf, Information Technology, Restful APIs
- **Published:** November 3, 2026
- **Apply:** https://www.dice.com/job-detail/d79b4b50-942c-4999-9e3c-9358859052bc

## About the Role

* 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 financial/accounting systems development or support, including double-entry posting, balance and accrual maintenance, value dating, reconciliation, and month-end close in a regulated environment.
 * 3+ years of experience working with Adabas and VSAM.
 * 3+ years of experience tracing undocumented logic through copybooks, call chains, and job streams.

Required Technical Expertise

 * Enterprise COBOL batch and online development, including enhancements to large existing applications.
 * NaturalOne development, debugging, and deployment, including local development and remote z/OS projects.
 * Natural programs, subprograms, maps, DDMs, descriptors, superdescriptors, and Adabas file design and performance.
 * JCL, procedures, GDGs, utilities, SORT, restart/rerun handling, and TSO/ISPF.
 * VSAM file design and access, and Adabas for z/OS.
 * Legacy system impact analysis and clear documentation of affected processing., * Cash management, treasury, account pooling, cash concentration, sweeps, or intercompany allocation experience.
 * CA-7 scheduling, batch operations, batch-window analysis, and performance tuning.
 * Integration between COBOL and Natural.
 * Mainframe integration through z/OS Connect, IBM MQ, or REST services.
 * REXX or CLIST for tooling, and Python or Java for data comparison and migration., * Ability to take specifications from analysis through production implementation with limited supervision.
 * Strong written communication skills for technical teams, business analysts, and auditors.
 * Degree in computer science or a related field, or equivalent practical experience.

## Description

Mainframe Developer - COBOL / NaturalOne / Adabas | 100% Remote, We are seeking an experienced Mainframe Developer with strong Enterprise COBOL, NaturalOne, Natural, Adabas, and JCL expertise to enhance financial and accounting applications on z/OS. The developer will deliver composite reservoir account (CRA) functionality, from legacy system analysis and design through testing, implementation, and early production support., * Analyze existing account master, posting, and balance-maintenance programs to identify and document changes needed to support CRAs.

 * Design and develop account structures, account opening and closing, participant linkage, sweep and reverse-sweep processing, allocation, interest apportionment, and closing balance calculations.
 * Modify batch COBOL programs and JCL, extending nightly and month-end processing within agreed batch-window limits.
 * Incorporate CRA processing into audit trails, exception reporting, and reconciliation controls in collaboration with accounting stakeholders.
 * Prepare test data, unit and regression test packs, and parallel-run comparisons against production output; investigate and explain discrepancies.
 * Support implementation, conversion of in-scope accounts, and initial production cycles, including on-call coverage.
 * Maintain program documentation, data-flow notes, and operational runbooks.
 * Follow formal change control, peer review, and approved implementation plans.