Senior Payments Systems Engineer - Postilion & ISO 8583

Computer Services, Inc. (CSI); Valparaiso (IN); On-site; USD 110,000 - 150,000; Full time

Benefits offered by this job

Competitive benefits

Career growth opportunities

Job summary

Computer Services, Inc. (CSI) seeks a Software Engineer with deep expertise in ACI Postilion Realtime SDK and payment network integrations to design, develop, and support high-volume processing systems.

You will work on routing, authorization, and settlement workflows, integrate with Visa, Mastercard, Pulse, NYCE, and STAR networks, and participate in on-call production support and security compliance efforts.

Qualifications

• 5+ years of software development experience in payments.
• Extensive hands-on work with ACI Postilion and Realtime SDK.
• Proven experience integrating payment networks and third-party processors.

Responsibilities

• Design, develop, and support high-volume payment processing solutions.
• Build interfaces between Postilion and external systems.
• Configure routing, authorization, settlement, and reconciliation functions.
• Provide Level 2/3 production support and incident resolution.
• Ensure PCI DSS and security-compliant practices.

Skills

ACI Postilion

ISO 8583 messaging

Java

SQL

TCP/IP networking

REST APIs

Tools

Postilion Realtime SDK

Postilion Office

HSM integrations

Job description

Computer Services, Inc. (CSI) seeks a Software Engineer with deep expertise in ACI Postilion Realtime SDK and payment network integrations to design, develop, and support high-volume processing systems.

You will work on routing, authorization, and settlement workflows, integrate with Visa, Mastercard, Pulse, NYCE, and STAR networks, and participate in on-call production support and security compliance efforts.