Senior Software Engineer

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 Mastercard is a global technology company in the payments industry, focused on powering an inclusive, digital economy that makes transactions safe, simple, smart, and accessible. Using secure data and networks, our innovations enable individuals, financial institutions, governments, and businesses worldwide to realize their greatest potential. Role Within Mastercard’s Builders Enablement Program (ONE Division), we are building a standardized, secure, cloud first software delivery ecosystem and delivering a world class developer experience. We are seeking a Senior Software Engineer to design, build, and enhance software applications and developer-facing experiences that empower engineers across Mastercard's software delivery ecosystem. This role requires deep expertise in software architecture, application development, user experience, and distributed systems, combined with full lifecycle ownership from design through production operations. About the Role Software Development

• Design, develop, test, and support scalable cloud-native applications and services
• Build and maintain backend solutions using Java and Spring Boot
• Develop and enhance modern user interfaces using React and TypeScript
• Design and implement REST APIs and service integrations across the Developer Experience ecosystem
• Build integrations with developer tools including Jenkins, GitHub, Bitbucket, SonarQube, Workday, and related engineering platforms
• Contribute to internal developer portals using Backstage or similar frameworks
• Help improve engineering productivity through automation, self-service capabilities, and platform standardization

Software Development Excellence

• Own delivery of robust, secure, and high-performance software across backend platforms and frontend applications (React, TypeScript)
• Drive engineering excellence in coding standards, modular design, and maintainability
• Design and develop software solutions that improve developer productivity and streamline software delivery workflows using Backstage or similar frameworks and extensible plugin-based architectures.
• Build modern, data-driven user experiences that transform engineering and operational data into actionable insights for software development teams.

Testing Strategy & Quality Engineering

• Define and implement comprehensive testing strategies, including:
• Unit testing
• Integration testing
• Functional/end-to-end testing
• Embed automated testing within CI/CD pipelines to enforce quality gates and prevent regressions
• Ensure systems meet correctness, reliability, and backward compatibility requirements at scale

Performance Engineering

• Lead performance engineering initiatives, including system benchmarking, load testing, and capacity planning
• Analyze application and service performance, optimize system responsiveness, and improve scalability across highly distributed software systems.
• Ensure applications meet strict performance SLAs in high-volume, mission-critical environments

Secure Coding & Compliance

• Enforce secure coding practices and integrate security into every phase of the SDLC
• Design systems that meet enterprise security, regulatory, and compliance requirements
• Partner with security teams to proactively identify and remediate vulnerabilities

Troubleshooting & Incident Management

• Serve as a senior technical leader for complex software production issues, leveraging deep troubleshooting expertise across distributed applications, APIs, integrations, and user-facing systems.
• Lead root cause analysis, incident resolution, and postmortem activities
• Drive systemic improvements to prevent recurring issues and improve system reliability

Code Review & Technical Leadership

• Lead rigorous code reviews, ensuring adherence to best practices in design, performance, security, and maintainability
• Mentor engineers and elevate team capability in software design, testing, debugging, and operational excellence
• Provide hands-on guidance in solving high-complexity technical problems across system layers

Collaboration & Ownership

• Partner with product, platform, and business stakeholders to shape technical roadmaps and delivery priorities
• Own and deliver cross-functional software engineering initiatives spanning frontend applications, backend services, APIs, integrations, and cloud-native architectures.
• Contribute to the Software Engineering Guild by sharing reusable frameworks, patterns, and innovations

All About You We are looking for someone who:

• Demonstrates proficient knowledge, skills, and experience across software development, system design, and architecture
• Advanced foundation in data structures, algorithms, and distributed systems
• Is equally comfortable working across backend platforms and frontend applications
• Maintains a quality-first mindset, emphasizing testing, security, and performance
• Excels at troubleshooting complex systems and driving resolution under pressure
• Proactively improves software quality, reliability, performance, and developer experience through thoughtful design and engineering best practices.
• Influences technical direction and mentors' engineers across teams

Qualifications:

• Demonstrated experience designing and developing scalable software systems using object-oriented design principles, modern software architecture patterns, and cloud-native development practices.
• Proficient experience in software development and system design, with demonstrated ownership of large-scale distributed systems

• Proficient expertise in:

• Software Design & Software Architecture
• Unit, Integration, and Functional Testing frameworks and strategies
• Operability engineering (observability, monitoring, reliability)

• Advanced hands-on experience with:

• Performance Engineering and system optimization
• Secure coding practices and application security principles
• Code reviews and engineering quality standards
• Data Structures & Algorithms
• Troubleshooting complex distributed systems
• Advanced proficiency in modern programming languages (e.g., Java, C#) and frontend development using React and/or TypeScript
• Experience designing extensible software architectures and integrating developer tools through APIs, plugins, and event-driven patterns.
• Experience with plugin-based architectures and integrating DevOps tools
• Proven ability to build data-driven user interfaces
• Hands-on experience developing and deploying cloud-native software using AWS, Kubernetes, containerized architectures, and modern engineering practices.
• Proficient experience with CI/CD pipelines and Infrastructure as Code (Terraform, CloudFormation)
• Experience with observability platforms (e.g., Splunk or equivalent)
• Excellent communication and technical leadership skills
• Bachelor’s or Master’s degree in Computer Science, Engineering, or related field preferred

Mastercard is a merit-based, inclusive, equal opportunity employer that considers applicants without regard to gender, gender identity, sexual orientation, race, ethnicity, disabled or veteran status, or any other characteristic protected by law. We hire the most qualified candidate for the role. In the US or Canada, if you require accommodations or assistance to complete the online application process or during the recruitment process, please contact View email address on click.appcast.io and identify the type of accommodation or assistance you are requesting. Do not include any medical or health information in this email. The Reasonable Accommodations team will respond to your email promptly. 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. In line with Mastercard’s total compensation philosophy and assuming that the job will be performed in the US, the successful candidate will be offered a competitive base salary and may be eligible for an annual bonus or commissions depending on the role. The base salary offered may vary depending on multiple factors, including but not limited to location, job-related knowledge, skills, and experience. Mastercard benefits for full time (and certain part time) employees generally include: insurance (including medical, prescription drug, dental, vision, disability, life insurance); flexible spending account and health savings account; paid leaves (including 16 weeks of new parent leave and up to 20 days of bereavement leave); 80 hours of Paid Sick and Safe Time, 25 days of vacation time and 5 personal days, pro-rated based on date of hire; 10 annual paid U.S. observed holidays; 401k with a best-in-class company match; deferred compensation for eligible roles; fitness reimbursement or on-site fitness facilities; eligibility for tuition reimbursement; and many more. Mastercard benefits for interns generally include: 56 hours of Paid Sick and Safe Time; jury duty leave; and on-site fitness facilities in some locations. THIS POSTING RELECTS ONE OR MORE CURRENT VACANCIES ON OUR TEAM, AND MASTERCARD INTENDS TO FILL THIS POSITION BY 12/10/2026. Pay Ranges O'Fallon, Missouri: $115,000 - $184,000 USD MasterCard