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

Senior Software Engineer

About the Role
As part of a fast-paced engineering team, you will help design, build, and deliver secure, scalable, and high-performing software solutions that support Mastercard's business-critical platforms. In this role, you'll take ownership of complex technical work, contribute to software design and architecture decisions, and help deliver reliable, production-ready systems. You'll collaborate closely with product, business, and engineering partners to translate requirements into solutions that are secure, maintainable, and built to scale. You'll also play an important role in strengthening engineering practices across the team, including code quality, testing, automation, performance, operability, and continuous improvement.


Role
-Design, build, test, deploy, and maintain scalable software applications and services
-Translate business and technical requirements into well-structured software designs
-Contribute to architecture decisions that support scalability, performance, security, and long-term maintainability
-Develop high-quality, secure, and maintainable code using modern engineering practices
-Own delivery tasks across the full software development lifecycle, including design, development, testing, deployment, configuration, and documentation
-Participate in team prioritization discussions with product and business stakeholders
-Estimate work, manage delivery commitments, and communicate progress clearly
-Lead and contribute to technical discussions, including design options, trade-offs, and implementation approaches
-Write and maintain unit, functional, integration, and service-level tests to ensure quality and reliability
-Improve test automation, code coverage, and overall software quality
-Analyze and optimize application performance, scalability, and reliability
-Apply secure coding practices and support vulnerability identification and remediation
-Use code quality, security scanning, and automation tools to identify risks and improve engineering outcomes
-Perform and lead code reviews to improve readability, maintainability, quality, and adherence to standards
-Troubleshoot and resolve complex issues across applications, systems, and environments
-Build systems with strong operability, including monitoring, logging, resiliency, and support readiness
-Contribute to CI/CD pipelines and release workflows that support reliable, efficient delivery
-Share knowledge, promote reuse of patterns and practices, and support continuous improvement across the team
-Mentor and guide less-experienced engineers through technical feedback and day-to-day collaboration
-Demonstrate Mastercard Way values by owning outcomes, simplifying complexity, moving with urgency, taking thoughtful risks, unlocking potential, and being inclusive


All About You
-Experience designing, building, testing, deploying, and maintaining software applications and services
-Strong understanding of software design principles and the ability to create scalable, maintainable, and secure solutions
-Experience contributing to software architecture decisions, including design patterns, system interactions, and technical trade-offs
-Ability to work independently on complex technical problems with limited guidance
-Strong understanding of data structures and how they impact performance, scalability, and system behavior
-Experience writing secure code and applying secure coding standards such as OWASP, CWE, or similar frameworks
-Experience identifying and addressing vulnerabilities as part of the software development lifecycle
-Strong experience with unit, functional, integration, and service-level testing
-Understanding of test automation strategies, including the test pyramid, behavior-driven development, and customer journey testing concepts
-Experience using code quality, security scanning, and software composition analysis tools such as Sonar, Checkmarx, Veracode, JFrog XRay, or similar tools
-Strong performance engineering skills, including analyzing, tuning, and optimizing systems for scalability, reliability, and efficiency
-Experience performing and leading code reviews to improve code quality, consistency, and maintainability
-Strong troubleshooting and root cause analysis skills in complex technical environments
-Experience building software with operability in mind, including monitoring, logging, alerting, reliability, and support readiness
-Experience with CI/CD pipelines, release workflows, build automation, and deployment practices
-Familiarity with deployment strategies such as canary or blue-green deployments
-Ability to collaborate effectively with product owners, business stakeholders, and engineering teams
-Strong communication skills with the ability to explain technical decisions and influence outcomes
-Experience mentoring, coaching, or supporting other engineers
-Bachelor's degree in Software Engineering, Computer Science, Information Technology, or related discipline preferred, or equivalent work experience


Nice to Have
-Experience with artificial intelligence, cloud, machine learning, or data-driven platforms
-Experience working on high-scale, mission-critical, or regulated technology platforms
-Experience in payments, financial services, or transaction-based environments
-Exposure to domain-driven design principles
-Experience improving engineering processes, tooling, frameworks, or shared libraries across teams

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.

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.

Pay Ranges
O'Fallon, Missouri: $115,000 - $184,000 USD