Senior Software Engineer
Mastercard · O'Fallon, Missouri
- Location
- O'Fallon, Missouri
- Salary
- $115,000 - $184,000 USD
- Experience
- 6+ years
- Funding
- Public Company • not captured
- Posted
- Sep 8, 2026
Mastercard is hiring a Senior Software Engineer based in O'Fallon, Missouri. Every apply link on Engg.space goes straight to the company's own careers page - no recruiter middleman, no generic job-board form.
Apply directly at MastercardRole details
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 At Mastercard, our technology and innovation are driven by a clear purpose: to build a sustainable, inclusive global economy. Our commitment to being a force for good is embedded in The Mastercard Way—the principles and behaviors that define who we are and how we deliver value to our customers, partners, and communities. We foster a highly collaborative and inclusive environment where employees are empowered to bring their full, authentic selves to work. By leveraging the diverse strengths, perspectives, and experiences of our global workforce, we continue to drive innovation at scale. Role Summary The Pricing & Billing Resource Center (PBRC) team develops and operates business-critical, API-driven platforms built on Java and Spring technologies. These platforms deliver highly scalable, secure, and reliable billing and pricing capabilities across Mastercard. As a Senior Software Engineer, you will develop engineering solutions that improve the correctness, performance, reliability, and operational readiness of PBRC applications. You will design reusable automation frameworks, validation capabilities, and diagnostic tools across API, UI, integration, and performance layers. Working throughout the software development lifecycle, you will collaborate with engineers, product teams, and business partners to identify risk, strengthen technical controls, accelerate delivery feedback, and improve confidence in every production release. Key Responsibilities Engineering Automation and Framework Development • Design, develop, and maintain reusable automation frameworks using Java and modern engineering practices. • Build software solutions that validate application behavior across API, UI, integration, and end-to-end workflows. • Develop reusable libraries, utilities, data generators, and service virtualization capabilities that improve engineering efficiency. • Apply object-oriented design principles, data structures, and software design patterns to create scalable and maintainable solutions. • Evaluate and incorporate tools such as REST Assured, Selenium, Cypress, Cucumber, Insomnia and SQL Developer where appropriate. API and Application Integrity • Develop automated solutions that verify REST API behavior, service interactions, data integrity, and user workflows. • Assess API contracts, schemas, business rules, error handling, boundary conditions, and failure scenarios. • Collaborate with application engineers to improve component-level, functional, integration, and end-to-end coverage. • Analyze complex distributed-system interactions and develop controls that detect regressions earlier in the delivery lifecycle. • Translate technical requirements and business scenarios into repeatable, measurable engineering outcomes. Performance and Reliability Engineering • Design and execute automated performance, load, stress, scalability, and resiliency assessments. • Establish and maintain engineering baselines for throughput, latency, resource utilization, and service reliability. • Use tools such as JMeter and BlazeMeter to identify system constraints and validate capacity expectations. • Partner with engineering teams to diagnose bottlenecks, troubleshoot complex issues, and implement sustainable improvements. • Contribute to application observability, operational readiness, production stability, and service-level objectives. Software Delivery and Operational Excellence • Integrate automated engineering controls into CI/CD pipelines to provide rapid feedback and support release decisions. • Develop efficient execution strategies, including parallel processing and environment-independent solutions. • Establish measurable quality gates that assess functional behavior, integration integrity, security, and performance. • Support root-cause analysis by providing clear diagnostics, reproducible evidence, and actionable technical findings. • Identify recurring failure patterns and develop automated mechanisms that prevent or detect recurrence. Engineering Standards and Technical Leadership • Contribute to software design and architecture decisions with a focus on scalability, maintainability, security, performance, and reliability. • Participate in code reviews to promote secure coding practices, engineering standards, and maintainable solutions. • Assess technical and delivery risks and recommend appropriate engineering controls. • Lead improvements to automation frameworks, development practices, and delivery processes. • Mentor engineers and promote shared ownership of product integrity throughout the software development lifecycle. • Partner across teams to continuously improve platform capabilities and customer outcomes. Required Qualifications • 6+ years of experience in software engineering, application development, engineering automation, or a related technical field. • Strong proficiency in Java, object-oriented programming, and software design principles. • Experience developing applications, frameworks, or engineering tools using Spring and Spring Boot. • Experience building automated validation capabilities across web, API, integration, and end-to-end workflows using Selenium, Cypress, or equivalent frameworks. • Experience building and maintaining reusable automation solutions for APIs, user interfaces, service integrations, or distributed systems. • Strong understanding of REST APIs, microservices architectures, API contracts, and data validati
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