Senior Software Engineer - Payments Platform Modernization

ACI Worldwide; Limerick; On-site; EUR 90,000 - 120,000; Full time

Job summary

ACI Worldwide is seeking an experienced Senior Software Engineer to join the MTS Development team responsible for a critical high-value payments platform. This role focuses on maintaining, enhancing, and modernizing core payment processing capabilities while supporting regulatory mandates, customer commitments, platform resiliency, and long-term product sustainability.

The ideal candidate will have experience in complex enterprise applications, payment systems, production support, and

Qualifications

• 8+ years of software development experience.
• Strong Java and enterprise application development experience.
• Experience with large-scale transaction processing platforms.
• Experience debugging complex production issues.
• Strong understanding of software architecture, integration patterns, APIs, and database technologies.
• Experience with secure software development practices.
• Excellent communication and collaboration skills.

Responsibilities

• Design, develop, and maintain core MTS platform capabilities.
• Deliver customer and regulatory commitments including payment network mandates.
• Participate in production issue resolution and root cause analysis.
• Support modernization initiatives including 64-bit migration, ISO 20022, structured address, security, and platform enhancement programs.
• Collaborate with Product Management, Professional Services, Quality Engineering, and Customer Support teams.
• Act as a technical mentor and support knowledge transfer initiatives.
• Drive engineering excellence through automation, testing, observability, and quality improvements.
• Leverage AI-assisted engineering tools to improve productivity and code quality.

Skills

Java

Enterprise apps

Transaction processing

Production debugging

Software architecture

APIs & integration patterns

Databases

Secure SDLC

Communication

Job description

ACI Worldwide is seeking an experienced Senior Software Engineer to join the MTS Development team responsible for a critical high-value payments platform. This role focuses on maintaining, enhancing, and modernizing core payment processing capabilities while supporting regulatory mandates, customer commitments, platform resiliency, and long-term product sustainability.

The ideal candidate will have experience in complex enterprise applications, payment systems, production support, and