Senior Software Engineer In Test Jobs in O Fallon, MO

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
Job Overview:
Responsible for the analysis, design, development, testing, and delivery of secure, scalable software solutions. Define requirements for new applications and customization adhering to Mastercard standards, processes, and best practices. Develop, customize, and test applications to integrate to Mastercard specifications. Provide leadership, mentoring, and technical training to other team members.
Major Accountabilities
• Plan, design, architect, and develop secure, scalable, and maintainable technical solutions and alternatives to meet business requirements in adherence with Mastercard standards, processes, and best practices
• Lead day-to-day system development and maintenance activities of the team to meet service level agreements (SLAs) and create solutions with a high level of innovation, cost effectiveness, quality, reliability, and faster time to market.
• Accountable for the full systems development life cycle including creating high-quality requirements documents, use cases, designs, and other technical artifacts including but not limited to detailed test strategies, performance benchmarking, release rollout and deployment plans, contingency/back-out plans, feasibility studies, cost and time analysis, and detailed estimates.
• Design, develop, test, deploy, and maintain software applications while applying software engineering best practices, secure coding standards, and effective use of data structures
• Perform system maintenance, production incident management, troubleshooting, root cause analysis, remediation, and on-call support while ensuring operational reliability and observability
• Select appropriate technical frameworks and solution delivery methodologies. Adapt technical artifact templates based on project and technology needs. Contribute ideas to help ensure required standards and processes are in place. Maintain solution and technology roadmaps
• Research and evaluate current and upcoming technologies and frameworks.
• Participate in PoCs (Proof of Concept) and help the department with selection of vendor solutions, technologies, methodologies, and frameworks.
• Collaborate with vendor resources for product support
• Conduct brownbag sessions on new and upcoming technologies, methodologies, and application-appropriate frameworks. Ensure knowledge transfer of vendor technology to Mastercard staff and provide technical training to team members
• Follow and promote Quality Assurance and Quality Control processes in the department. Actively look for opportunities to enhance standards and improve process efficiency. Mentor and guide team members during all phases of the SDLC
• Ensure adequate test coverage through unit, functional, integration, and performance testing. Perform quality inspections and walkthroughs throughout the SDLC including requirements reviews, design reviews, code reviews, and security reviews to ensure compliance with Mastercard standards.
• Coordinate offshore development and manage day-to-day activities.
All About You
• Strong understanding of software design, architecture, data structures, secure development practices, testing, and performance optimization.
• Strong programming and automation skills using Java, Groovy, or similar languages
• Experience designing, building, testing, deploying, and maintaining software applications using engineering best practices.
• Strong understanding of service-oriented, microservices, and API-driven architectures
• Experience building and supporting scalable backend services, APIs, and distributed systems
• Experience designing, building, and maintaining CI/CD pipelines to enable reliable, automated, and high-quality software delivery.
• Hands-on experience with DevOps tools such as Git/Bitbucket, Jenkins, XLR, Chef, Artifactory, Docker Registry, and similar platforms
• Experience automating infrastructure provisioning, configuration management, deployments, and operational workflows
• Knowledge of observability, monitoring, logging, production support, and security best practices including authentication, authorization, secure API design, and data protection
• Ability to collaborate effectively in a globally distributed engineering environment to improve software delivery processes
• Demonstrate a continuous learning mindset with interest in AI-driven automation, innovation, and operational efficiency
Education
• Bachelor's degree in Information Systems, Information Technology, Computer Science, Engineering, or equivalent work experience.
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: $115,000 - $184,000 USD