Job Summary The Mainframe Payments Developer will maintain, enhance, and support Fiserv PEP applications within an ACH payments environment. The role requires strong mainframe development expertise along with hands-on Fiserv PEP experience and a solid understanding of ACH payment processing, NACHA formats, settlement, returns, corrections, and exception processing. The developer will implement technical and business-driven changes, troubleshoot production issues, and support reliable ACH transaction processing. Key Responsibilities • Support, maintain, and enhance Fiserv PEP applications. • Develop and implement technical and business-driven changes using COBOL, JCL, DB2, CICS, VSAM, and related mainframe technologies. • Analyze and resolve ACH processing issues, defects, and production incidents. • Understand and support end-to-end ACH payment flows, including settlement, returns, corrections, and exception processing. • Work with NACHA file formats, ACH rules, and transaction processing requirements. • Troubleshoot payment failures, processing bottlenecks, and settlement reconciliation issues from both technical and functional perspectives. • Perform root cause analysis and coordinate issue resolution with business and operations teams. • Support production stability and ensure smooth ACH transaction processing. Required Qualifications • Strong mainframe development experience with COBOL, JCL, DB2, CICS, and VSAM. • Hands-on experience with Fiserv PEP. • Solid knowledge of ACH payments, NACHA formats, and ACH processing workflows. • Strong understanding of ACH settlement, returns, corrections, reconciliation, and exception processing. • Ability to troubleshoot payment failures, processing bottlenecks, and settlement reconciliation issues from both technical and functional perspectives. • Strong analytical and problem-solving skills. • Strong communication and collaboration skills.