Software Engineer II in Test (SDET)

Our Purpose
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.
Title and Summary
Software Engineer II in Test (SDET)
Who is Mastercard
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.
Overview
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 handson 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)
As an SDET, you will:
Own endtoend quality for application components, including test design, automation, execution, and reporting.
Develop highquality, 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 rootcause 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 knowledgesharing 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).
Handson 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
Ability to design test plans, test cases, and test data for functional and nonfunctional requirements.
Familiarity with design patterns (factory, adapter, singleton, observer, strategy, IoC).
Experience testing different application types: APIs, eventdriven services, batch jobs, web apps, bigdata pipelines.
Soft Skills
Strong problemsolving 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 comes 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.