This role is for Principal-level Mainframe z/OS Engineer to take end-to-end ownership of critical trading, valuation, and fund accounting platforms. These systems directly support portfolio valuation, financial reporting, and regulatory obligations where accuracy and reliability are non-negotiable. This role involves designing and managing core financial processing logic across: End-to-end trade lifecycle (capture through settlement) Fund accounting and investment book of record Daily/monthly NAV computation and financial close Audit replay, historical restatement, and regulatory correction workflows The ideal candidate brings deep domain expertise in capital markets, strong batch engineering capabilities, and a track record of delivering highly accurate, high-volume financial systems under strict regulatory oversight. Required Skills & Experience 18+ years of hands-on mainframe application development Advanced expertise in: Enterprise COBOL (high-precision financial calculations, packed decimal handling) DB2 for z/OS (complex SQL tuning, performance engineering) CICS TS and/or IMS TM transaction processing JCL, PROCs, and enterprise batch processing frameworks Strong experience across: Trading and post-trade processing systems Investment accounting and fund administration platforms NAV calculation and valuation engines Demonstrated ownership of production-critical financial applications Expertise in: Accounting close cycles and NAV processing Reconciliation workflows and break resolution Corporate actions lifecycle management Multi-currency valuation and FX rate application Experience with scheduling and deployment tools: Control-M, CA-7, or Tivoli Workload Scheduler Endevor, Changeman (or similar SCM tools) Hands-on exposure to: Audit replay and historical data restatement frameworks Large-scale asset manager or custodian environments Key Responsibilities Lead the architecture and development of Enterprise COBOL applications supporting: Trade capture, settlement, and lifecycle processing Position, holdings, and cash accounting systems Daily, monthly, and ad-hoc NAV calculations Take full ownership of financial accuracy and data integrity across systems Design and implement restartable, checkpoint-driven batch frameworks for financial close processes, including: Multi-currency valuation and FX conversions Income accruals, amortization, and distribution calculations Corporate actions such as dividends, splits, and mergers Build systems capable of reprocessing historical data for audit, reconciliation, and regulatory corrections Troubleshoot and resolve NAV breaks and accounting discrepancies within strict reporting deadlines Design and optimize DB2 data models for: High-volume trade, position, and pricing datasets Historical valuation and reporting data Perform advanced performance engineering: EXPLAIN plan analysis Access path tuning Index strategy optimization Address production challenges including locking issues, batch overruns, and data skew Develop scalable batch processing solutions with parallel execution capabilities for EOD/EOM cycles Optimize COBOL programs for performance, focusing on CPU utilization, I/O efficiency, and consistent processing windows Build and maintain integration layers using IBM MQ for: Trade and pricing feeds Market data ingestion Downstream accounting and reporting systems Deliver data feeds for risk management systems and regulatory reporting platforms Support API enablement initiatives via z/OS Connect EE Act as the technical owner for high-impact financial components and lead root-cause investigations for: Financial inconsistencies Reconciliation breaks Batch and online processing failures Support SOX, SEC, and internal audits by ensuring complete traceability and replay capability of financial processing logic