Software Engineer II in Test (SDET) in Dublin

Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we’re helping build a sustainable economy where everyone can prosper. We support a wide range of digital payments choices, making transactions secure, simple, smart and accessible. Our technology and innovation, partnerships and networks combine to deliver a unique set of products and services that help people, businesses and governments realize their greatest potential.

Mastercard is a global technology company in the payments industry. Our mission is to power an inclusive, digital economy that benefits everyone by making transactions safe, simple, smart, and accessible. With secure data, global networks, and deep partnerships, we help individuals, financial institutions, governments, and businesses realize their greatest potential. Our culture is driven by our decency quotient (DQ), guiding how we work and innovate across more than 210 countries and territories.

The Decision Management Program (DMP) delivers intelligent, realtime decisioning products using streaming analytics, business rules engines, AI models, and largescale distributed systems. These capabilities help prevent fraud and enable trusted transactions across the Mastercard network.

We are seeking an SDET (Software Engineer II) with 4+ years of hands-on engineering and automation experience to join the Decision Operations team in Dublin. This role blends strong software engineering skills with deep quality engineering expertise to ensure our decisioning systems are reliable, scalable, and secure.

Role (What You Will Do)

• Own end-to-end quality for application components, including test design, automation, execution, and reporting.
• Develop high-quality, secure, and testable code for backend services, REST APIs, and supporting components.
• Build and maintain automated test suites (unit, integration, functional, regression, mutation testing).
• Contribute to CI/CD pipelines by integrating automated tests and quality gates.
• Participate in Agile ceremonies and collaborate closely with developers, architects, and product teams.
• Troubleshoot production issues, perform root-cause analysis, and implement corrective/preventive actions.
• Conduct code reviews, refactor test and application code, and contribute to technical documentation.
• Advocate for best practices in testability, automation, secure coding, and continuous improvement.
• Support engineering guilds and knowledge-sharing initiatives.

All About You (What You Bring)

Technical Skills

• Full stack tester with strong programming skills with the ability to write secure, maintainable code (Java, SQL, or similar).
• Hands-on experience with Spring Boot, microservices, and distributed system patterns.
• Deep understanding of automated testing across levels:

• Unit testing (JUnit, Mockito)
• Service/API testing
• Integration and functional testing
• Regression and mutation testing

Soft Skills

• Strong problem-solving and debugging skills.
• Ability to manage multiple tasks and deliver within business timelines.
• Passion for quality, automation, and continuous improvement.
• Strong communication and collaboration skills.

Desirable Skills

• Experience with CI/CD tools (Jenkins, GitHub Actions), monitoring tools (Splunk, Dynatrace), and performance testing (JMeter).
• Exposure to cloud platforms (AWS, Azure, GCP), Docker, Kubernetes.
• Experience with Redis, Kafka, or other distributed data technologies.
• Knowledge of secure coding standards (OWASP, CWE, SEI CERT).
• Familiarity with code quality and security scanning tools (Sonar, Checkmarx, Black Duck, Zally).

Corporate Security Responsibility

All activities involving access to Mastercard assets, information, and networks come with an inherent risk to the organization and, therefore, it is expected that every person working for, or on behalf of, Mastercard is responsible for information security and must:

• Abide by Mastercard’s security policies and practices;
• Ensure the confidentiality and integrity of the information being accessed;
• Report any suspected information security violation or breach, and
• Complete all periodic mandatory security trainings in accordance with Mastercard’s guidelines.