> Markdown version of [/jobs/ext/3715442-payments-systems-mainframe-engineer](https://www.wearedevelopers.com/jobs/ext/3715442-payments-systems-mainframe-engineer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Payments Systems Mainframe Engineer - **Company:** HEITMEYER CONSULTING INC - **Location:** Buffalo, NY, United States (Remote available) - **Experience:** Expert - **Contract:** Temporary contract - **Skills:** Microsoft Windows, Customer Information Control System (CICS), COBOL (Programming Language), IBM DB2, Payment Systems, Job Control Language (JCL), Payment Gateway, Reverse Engineering, Tokenization, Transaction Processing (Computing), Cloud Platform System, Software Troubleshooting, Base 24 EPS - **Published:** October 13, 2026 - **Apply:** https://www.heitmeyerconsulting.com/submit-your-resume/ ## About the Role * Extensive experience with Base24 (TAL) or Postilion * Deep knowledge of card processing and electronic payments systems. * Experience with: + Authorization routing + Debit networks + Payment switching and transaction processing + Payment platform architecture * Strong understanding of: + Encryption technologies + Tokenization + Payments security concepts * Hands-on development experience in COBOL mainframe environments with JCL, CICS, DB2 * Must have an architectural mindset and strong troubleshooting abilities, with experience navigating mainframe environments, analyzing COBOL/CICS applications, performing root cause analysis, reverse engineering complex issues, and assessing the downstream impact of system changes. * Experience working within Windows-based platforms. * Ability to analyze complex systems and provide architectural guidance and recommendations. * Excellent problem-solving and communication skills.??????? ## Description We are seeking a highly experienced Senior Base24 Payments Engineer to join the Legacy Base24 team supporting the existing ATH platform. This role is ideal for a seasoned payments professional with deep expertise in card processing, authorization systems, and transaction routing who can contribute strategically beyond hands-on development. The successful candidate will play a key role in maintaining and enhancing critical payment processing systems while providing architectural guidance and technical leadership across the platform., * Support and enhance the legacy ACI Postilion (formerly Base24) environment supporting the ATH platform. * Design, develop, and maintain payment transaction processing solutions. * Provide expertise in authorization routing, debit network integrations, and card transaction processing. * Collaborate with technical and business stakeholders to evaluate and implement system improvements. * Contribute to architecture discussions and provide recommendations for platform modernization and optimization. * Troubleshoot and resolve complex production issues related to payment processing systems. * Ensure compliance with security, encryption, tokenization, and payment industry best practices. * Support integration efforts across mainframe and distributed platform environments.