Senior Software Engineer

Mastercard · O'Fallon, Missouri

onsitefull-time6-10 years

posted 22h

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 Overview Join a team responsible for building the authentication and security solutions that help protect digital interactions across Mastercard's Identity Solutions platform. As a Senior Software Engineer, you will design, develop, and support secure, scalable, and high-performing applications that enable trusted identity verification, authentication, and fraud prevention capabilities. In this role, you will take ownership of complex technical challenges, contribute to software design and architecture decisions, and partner closely with product, security, and platform teams to deliver reliable, production-ready solutions. You'll play a key role in advancing engineering excellence through secure development practices, system reliability, automation, and continuous improvement while mentoring other engineers and influencing technical direction across the team. Role •Design, build, test, deploy, and maintain scalable, cloud-native applications and microservices •Develop REST APIs using Java and Spring Boot, focusing on performance, scalability, and reliability •Translate requirements into well-structured designs and architecture, ensuring maintainability and security •Lead and contribute to system design discussions, aligning with architectural standards and best practices •Write and maintain unit, functional, and integration tests to ensure quality and reliability •Drive improvements in test automation, code coverage, and system reliability •Analyze and optimize system performance, scalability, and efficiency •Apply secure coding practices and lead vulnerability remediation efforts (CVE remediation, upgrade automation) •Perform and lead code reviews to improve code quality, maintainability, and adherence to standards •Troubleshoot and resolve complex production issues using structured problem-solving and root cause analysis •Ensure systems are built with strong operability (monitoring, logging, reliability, support readiness) •Contribute to CI/CD pipelines and engineering practices that improve delivery speed and quality •Collaborate across teams (product, QA, platform) to deliver high-quality solutions •Mentor junior engineers and support knowledge sharing across the team •Contribute to a culture of continuous improvement, accountability, and collaboration All About You •Experience building RESTful services using Java and Spring Boot •Strong experience designing scalable systems using modern software design and architecture principles •Experience with cloud platforms (AWS, Azure, or GCP) and containerization (Docker, Kubernetes) •Proven ability to work independently on complex technical problems and support team outcomes •Experience writing and maintaining unit, functional, and integration tests •Strong understanding of performance engineering (analyzing and optimizing systems at scale) •Expertise in secure coding practices and vulnerability management •Experience leading and contributing to code reviews and engineering standards •Strong troubleshooting and root cause analysis skills in complex environments •Solid understanding of data structures and their impact on performance and scalability •Experience building systems with strong operability, monitoring, and reliability practices •Experience working in Agile/Scrum environments and collaborating across teams •Strong communication and collaboration skills, with the ability to influence technical decisions •Experience mentoring or