Job Title: FIS Connex Payment Switch Developer
Location: Houston TX or Remote
Long Term Contract
Rate: Only W2/1099 Profiles
Job Summary
We are seeking an experienced FIS Connex Payment Switch Developer to support and enhance our card payment switching platform. The role focuses on real-time transaction processing, ISO 8583 messaging, and integrations with card networks, core banking systems, ATMs, POS, and digital payment channels. This is a mission-critical role within a high-availability payments environment.
Key Responsibilities
Develop, configure, and maintain the FIS Connex payment switch
Design and support ISO 8583 message flows for ATM, POS, and e-commerce transactions
Configure transaction routing, validation, and response handling
Integrate Connex with:
Core banking systems
Card schemes (Visa, Mastercard, domestic networks)
ATM/POS networks and payment gateways
Perform field mapping, message transformation, and protocol validation
Troubleshoot transaction issues including declines, reversals, and timeouts
Support UAT, certification testing, and production deployments
Work with HSMs for PIN processing, key management, and cryptographic services
Ensure compliance with PCI-DSS and internal security standards
Provide L2/L3 production support and incident resolution
Maintain technical documentation and configuration records
Required Skills & Experience
Hands-on experience with FIS Connex
Strong knowledge of ISO 8583
Experience with C, C++, or Java
Solid experience in Linux/Unix environments
Understanding of TCP/IP and socket-based communication
Experience integrating with HSMs (e.g., Thales, SafeNet, Futurex)
Database experience (Oracle, DB2, PostgreSQL, or similar)
Strong troubleshooting and analytical skills
Payments Domain Knowledge
Card transaction lifecycle (authorization, clearing, settlement)
ATM and POS transaction processing
Reversals, advice messages, and exception handling
Interbank and card network routing concepts
Basic understanding of fraud and risk controls
Preferred Qualifications
Experience with other FIS payment products
Visa and/or Mastercard certification experience
Experience in banking, fintech, or payment processing environments
Familiarity with 24/7, high-availability systems
Knowledge of reconciliation and settlement processes
Education
Bachelor s degree in Computer Science, Information Technology, or related field (or equivalent practical experience)