Senior Software Engineer (API) – Fraud Platform

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

Senior Software Engineer (API) – Fraud Platform

SENIOR SOFTWARE ENGINEER (JAVA) — DATA CACHING / DISTRIBUTED SYSTEMS

Location: Dublin, Ireland

OVERVIEW
We are hiring a Senior Java Software Engineer to join a Dublin-based engineering team working on Mastercard's real-time decisioning platform. The team designs, builds and operates a high-performance, distributed, in-memory data caching layer that supports mission-critical transaction processing at global scale, with a strong focus on low latency, high availability and resiliency.

This is a hands-on senior role for an engineer who enjoys working close to complex distributed systems, owning features end-to-end, and helping shape technical direction within a collaborative Agile team.

• Want to work on industry-leading, mission-critical distributed systems at global scale?
• Motivated by solving complex performance, resiliency and data-consistency problems?
• Keen to take end-to-end ownership and mentor others in a high-trust team?

ROLE & KEY RESPONSIBILITIES
As a Senior Software Engineer, you will act as a technical owner and leader within the team:

• End-to-end delivery — Own complex features and services across the full software development lifecycle: architecture, design, development, testing, deployment, rollback planning and documentation.
• Design & innovation — Design and implement high-performance, scalable and secure Java capabilities; apply advanced design patterns and API standards; produce high- and low-level design documentation to a professional standard.
• Independent problem-solving — Drive solutions for complex problems; debug and troubleshoot across multi-tiered systems, including core, heap and thread-dump analysis; design resilient solutions.
• Technical leadership & influence — Lead code, design and process trade-off discussions; drive adoption of coding standards and frameworks; review code, tests and automation produced by other team members.
• Release & delivery coordination — Support coordinated releases across a follow-the-sun, multi-region engineering model, including scope tracking, cross-team sign-offs and release execution.
• Operational excellence — Participate in on-call support; lead incident management, root-cause analysis and remediation; proactively improve performance and stability metrics.
• Stakeholder engagement — Contribute to prioritisation with Product and Business stakeholders; lead demos and acceptance discussions with Product Owners; report status and manage risks in owned service areas.
• Mentoring & knowledge sharing — Mentor less-experienced engineers, deliver knowledge-transfer and brown-bag sessions, and help build shared understanding across the team.
• Continuous improvement — Identify inefficiencies and drive automation of build, operate and run activities; research and evaluate emerging technologies and frameworks.

REQUIRED SKILLS & EXPERIENCE
• Strong proficiency with modern Java (JDK 17 or later); distributed systems and multi-threading experience.
• Experience with Spring, Spring Boot, Hibernate, RESTful APIs, JSON; application servers (e.g. JBoss/Tomcat); Shell scripting.
• Experience with distributed caching or in-memory data grid technologies (e.g. Apache Geode, Hazelcast, Redis, Coherence) is highly desirable.
• Solid experience with Linux, SQL and message-queuing systems, and with design patterns.
• Expertise in JUnit or equivalent automated testing frameworks; designing test plans across unit, regression, performance and integration.
• CI/CD proficiency — tools such as Jenkins and Maven; source control in a multi-developer, distributed environment.
• Familiarity with observability and monitoring tooling for alerting, dashboards and performance analysis.
• Understanding of secure development practices (secure-by-design) and awareness of PCI-DSS considerations for handling payment card data.
• Passionate about Agile ways of working (SAFe / SCRUM), code quality and engineering best practices.

OTHER ATTRIBUTES
• Excellent written and verbal communication and strong cross-team, cross-geography collaboration.
• Shows initiative, takes on challenging opportunities, and demonstrates en