Mainframe Developer

Job Title: Mainframe Developer – Composite Reservoir Accounts (14507) Location: Columbia, SC 100% Remote Duration: 6 Months (Possible Extension) Interview: 1–2 Rounds of Virtual Interviews Candidate Location: Must reside within the 48 contiguous United States. South Carolina residency is not required. Must be comfortable working EST hours. Required Skills 5+ years of Enterprise COBOL development experience in a z/OS environment. 5+ years of hands-on experience with NaturalOne. 5+ years of JCL development and production support experience. 3+ years of financial/accounting systems development or support, including double-entry posting, balance/accrual maintenance, value dating, reconciliation, and month-end closeouts in a regulated environment. 3+ years of experience working with Adabas and VSAM. 3+ years of experience tracing undocumented legacy logic through COBOL copybooks, program call chains, and JCL job streams. 3+ years of hands-on experience with Composite Reservoir Accounts. Preferred Skills Experience with cash management, account pooling, sweeps, or treasury applications. Experience with CA-7 scheduling and batch operations. Experience with REXX, Python, or Java. Experience integrating COBOL and Natural applications using z/OS Connect, IBM MQ, or REST services. Experience with batch window analysis, performance tuning, and production scheduling. Knowledge of notional and physical pooling, cash concentration, and intercompany allocation. Key Responsibilities Analyze existing COBOL account master, posting, and balance-maintenance programs to identify changes required for Composite Reservoir Accounts. Design, develop, and implement Composite Reservoir Account structures, including master account files, subsidiary account relationships, participant linkage, and account opening/closing functionality. Develop sweep and reverse-sweep processing logic to transfer and allocate funds between reservoir accounts and participating subsidiary accounts. Enhance financial accounting applications supporting double-entry posting, balance maintenance, interest accrual calculations, value dating, and reconciliation. Modify existing Enterprise COBOL batch programs and JCL job streams to incorporate new processing within nightly and month-end accounting cycles. Develop and maintain NaturalOne/Natural/Adabas applications, including Natural programs, subprograms, maps, DDMs, descriptors, and superdescriptors. Investigate undocumented legacy COBOL logic through copybooks, call chains, and job streams to identify dependencies and assess the impact of system enhancements. Implement financial controls, audit trails, exception reporting, and reconciliation processes to maintain accuracy and traceability. Optimize batch processing and ensure new functionality does not exceed agreed processing windows. Develop test data and conduct unit testing, regression testing, and parallel-run comparisons against existing production results. Investigate transaction discrepancies, balance differences, and interest-allocation issues before production implementation. Support account conversion, production deployment, early-life processing, and troubleshooting of financial applications. Prepare technical documentation, data-flow diagrams, implementation plans, and operational runbooks. Key Technical Expectations Candidates should be prepared to demonstrate expertise in: Enterprise COBOL / z/OS: Developing and enhancing complex batch and online programs within established production systems. NaturalOne / Natural / Adabas: Eclipse-based development, debugging, deployment, Natural programs, DDMs, descriptors, and Adabas data structures. JCL / Mainframe Operations: JCL, PROCs, GDGs, SORT utilities, TSO/ISPF, restart/rerun handling, and production batch troubleshooting. Financial Accounting: Double-entry posting, balance/accrual maintenance, value dating, financial reconciliation, and month-end closing. Composite Reservoir Accounts: Pooled-account structures, reservoir-to-participant linkage, cash sweeps, reverse sweeps, allocation rules, and interest apportionment. Legacy System Analysis: Tracing undocumented COBOL copybooks, program call chains, and job streams to determine the impact of production changes. About Us: InterSources Inc , is a Small, Woman, and Minority-Owned Business Enterprise, ISO/IEC 27001, SOC 2 Type 2 certified company with massive 18+ years of diversified experience in providing IT Consulting Services, Artificial Intelligence, Data Analysis, Application Development, Cloud Services, Cybersecurity, Digital Marketing, ERP Management, Custom Software Development, Web Development, UI/ UX Design, System Integration, QA Support etc. We make reasonable accommodations for clients and employees, and we do not discriminate based on any protected attribute including race, religion, color, national origin, gender sexual orientation, gender identity, age, or marital status. We also are a Google Cloud and Oracle partner company.