Mainframe Developer

Position Overview

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.

Key Responsibilities

• 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.

Required Qualifications

• 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.

Preferred Qualifications

• 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.

Additional Qualifications

• 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.