Mainframe Developer

Mainframe Developer – Composite Reservoir Accounts

Role Overview

100% Remote contract role to design, build, and integrate a new pooled-account structure (Composite Reservoir Accounts) into an existing z/OS mainframe accounting platform. You will extend legacy COBOL and Natural/Adabas applications so that subsidiary account balances concentrate and sweep accurately while maintaining strict double-entry posting, accrual, and audit traceability.

Location & Work Setup

• Location: Columbia, SC (100% Remote — Continental US residents only)
• Arrangement: 100% Remote
• Interview: 1–2 Rounds of Virtual Interviews
• Shift: EST

Crucial Responsibilities

• End-to-End Account Engineering: Design and code master file structures, account opening/closing, participant linkage, sweep/reverse-sweep rules, interest apportionment, and closing balance derivation.
• Legacy Code & Batch Modification: Analyze lightly documented COBOL/Natural codebases; modify batch COBOL programs and JCL to support nightly and month-end processing within existing batch windows.
• Controls & Reconciliation: Build audit trails, exception reporting, and reconciliation controls; run parallel comparisons against production output to ensure zero penny discrepancies.
• Documentation & Support: Produce unit/regression test packs, data-flow notes, and runbook updates, providing on-call cover during early-life production cycles.

Core Qualifications & Stack

• Enterprise COBOL (z/OS): 5+ Years (Batch and online production development)
• NaturalOne & Natural/Adabas: 5+ Years (Software AG Eclipse IDE, DDMs, descriptors/superdescriptors, file performance)
• JCL & z/OS Utilities: 3–5 Years (Procs, GDGs, SORT, restart/rerun handling, TSO/ISPF)
• Mainframe Data Stores: 3+ Years (VSAM file design/access and Adabas)
• Financial Accounting Systems: 3+ Years (Double-entry posting, accruals, value dating, month-end closeouts)
• Composite Reservoir Accounts: 3+ Years (Pooled accounts, sweep and allocation structures)
• Legacy Analysis: 3+ Years (Tracing undocumented logic across copybooks, call chains, and job streams)
• Preferred Skills: Cash management/treasury pooling, CA-7 scheduling, REXX/Python/Java, z/OS Connect, or IBM MQ.

Must-Have Constraints

• Must physically reside in the Continental United States (Lower 48 states) and work EST hours.
• Must have verifiable hands-on experience with Composite Reservoir Accounts (3+ years).