Software Engineer II — O'Fallon, Missouri

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 The Core Payments department is hiring a highly motivated Software Engineer II with a passion for Artificial Intelligence, Machine Learning, and Generative AI technologies. This role is responsible for designing, developing, testing, deploying, and maintaining scalable software solutions that leverage AI capabilities to solve business problems, improve operational efficiency, and create innovative customer experience. The ideal candidate combines strong software engineering fundamentals, system design expertise, and experience building enterprise-grade applications and service with proficient familiarity with AI/ML technologies, cloud platforms, and modern development practices to build production-ready AI-enabled applications. Key Responsibilities Software Development • Design, develop, test, deploy, and maintain scalable software applications and services. • Build APIs, microservices, and distributed systems that integrate with AI and Machine Learning capabilities to support business-critical applications. • Write clean, maintainable, reusable, and well-documented code following engineering best practices. • Apply software design principles and architectural patterns to develop scalable and reliable solutions. • Collaborate with product managers, architects, developers, and business stakeholders to deliver high-quality software solutions. • Experience leveraging AI-assisted development tools such as Claude Code and GitHub Copilot to improve engineering productivity and code quality. • Experience designing, developing, and utilizing AI agents, skills, and Model Context Protocol (MCP) integrations to automate workflows and enhance application capabilities. • Implement CI/CD pipelines for AI applications and software services. • Automate testing, deployment, monitoring, and operational support processes. • Ensure high availability, security, and performance of AI-enabled applications Software Architecture & Design • Contribute to software architecture decisions and technical designs that promote scalability, maintainability, security, and performance. • Evaluate technical solutions and recommend appropriate technologies, frameworks, and design patterns. • Develop system integrations and services that support enterprise application ecosystems. • Design solutions that support future growth while minimizing technical debt. Testing & Quality Engineering • Develop and maintain unit, integration, and functional tests to ensure software quality and reliability. • Implement automated testing practices within CI/CD pipelines. • Participate in code reviews to improve code quality, maintainability, and adherence to development standards. • Promote engineering best practices, coding standards, and continuous improvement initiatives. Performance & Reliability Engineering • Monitor and optimize application performance, scalability, and resource utilization. • Identify performance bottlenecks and implement improvements to enhance system efficiency. • Design applications for resiliency, fault tolerance, and high availability. • Support performance testing, capacity planning, and operational readiness activities. Secure Software Engineering • Apply secure coding practices and security-by-design principles throughout the development lifecycle. • Identify and remediate software vulnerabilities and technical risks. • Ensure applications comply with organizational security, compliance, and governance requirements. • Partner with security teams to address software and infrastructure security concerns. Operability & Support • Implement logging, monitoring, alerting, and observability capabilities to support operational excellence. • Troubleshoot and resolve software defects, production issues, and system incidents. • Support deployment automation, release management, and operational support activities. • Contribute to system reliability, maintainability, and continuous service improvement initiatives. All About You • Proficient experience developing backend software applications with JAVA/ J2EE in Spring Boot frameworks for building and consuming RESTful APIs and event-driven architectures. • Knowledge of Microservice architecture • Proficient knowledge and experience working with SQL and Relational Data Concepts • Experience designing and building scalable software applications and distributed systems. • Proficient knowledge of software design principles, object-oriented programming, and software architecture patterns. • Experience with source control systems, code review processes, and modern development practices. • Experience applying data structures, algorithms, and computational problem-solving techniques to develop efficient, scalable software solutions. • Experience implementing automated testing and CI/CD practices. • Experience developing cloud-native applications and services. • Experience working with containerization and orchestration technologies. • Familiarity with monitoring, observability, and application performance management tools. • Proficiency working with AI-enabled applications, automation solutions, or intelligent services within enterprise software environments. • Experience utilizing AI-assisted development tools such as GitHub Copilot or similar engineering productivity solutions. • Proficient analytical, troubleshooting, and problem-solving skills. • Excellent collaboration and communication skills. • Bachelor's or master's degree in computer science, Software Engineering, or a related technical 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 reasonable_accommodation@mastercard.com 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. Pay Ranges O'Fallon, Missouri: $92,000 - $147,000 USD