Senior Software Engineer

Mastercard•O'fallon, MO

2d•$115,000 - $184,000

About The Position

Mastercard is hiring a Senior Software Engineer within its Builders Enablement Program (ONE Division) to help build a standardized, secure, cloud-first software delivery ecosystem and provide a world-class developer experience. The engineer will design, build, and enhance software applications and developer-facing experiences used across Mastercard’s software delivery ecosystem, with full lifecycle ownership from design through production operations. The role works across backend services, frontend applications, APIs, integrations, and cloud-native architectures. It includes developing Java and Spring Boot backend solutions, React and TypeScript interfaces, REST APIs, integrations with developer and engineering platforms, and internal developer portal capabilities using Backstage or similar frameworks. The engineer will improve engineering productivity through automation, self-service capabilities, platform standardization, extensible architectures, and data-driven user experiences. The position emphasizes software quality, testing, performance, security, reliability, and operational excellence. The engineer will establish testing strategies, embed automated testing in CI/CD pipelines, improve application performance and scalability, support compliance requirements, and lead troubleshooting, incident resolution, root cause analysis, and postmortems for complex production issues. The role also provides technical leadership through code reviews, mentorship, cross-functional collaboration, and contributions to the Software Engineering Guild. Mastercard describes itself as a merit-based, inclusive, equal opportunity employer. The posting says the position is intended to be filled by 12/10/2026, or as soon as possible if that date has passed. For a U.S. position, the stated base salary range for O’Fallon, Missouri, is $115,000–$184,000 USD, with potential eligibility for an annual bonus or commissions depending on the role.

Requirements

Demonstrated experience designing and developing scalable software systems using object-oriented design principles, modern software architecture patterns, and cloud-native development practices.
Proficient software development and system design experience, including ownership of large-scale distributed systems.
Proficient knowledge of software design and software architecture.
Proficient knowledge of unit, integration, and functional testing frameworks and strategies.
Proficient knowledge of operability engineering, including observability, monitoring, and reliability.
Advanced hands-on experience with performance engineering and system optimization.
Advanced hands-on experience with secure coding practices and application security principles.
Advanced hands-on experience with code reviews and engineering quality standards.
Advanced knowledge of data structures and algorithms.
Advanced hands-on experience troubleshooting complex distributed systems.
Advanced proficiency in modern programming languages such as Java or 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 tools such as Terraform or CloudFormation.
Experience with observability platforms such as Splunk or equivalent.
Excellent communication and technical leadership skills.
Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field is preferred.

Nice To Haves

Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field.

Responsibilities

Design, develop, test, and support scalable cloud-native applications and services.
Build and maintain backend solutions using Java and Spring Boot.
Develop and enhance user interfaces using React and TypeScript.
Design and implement REST APIs and service integrations across the Developer Experience ecosystem.
Integrate developer tools and engineering platforms, including Jenkins, GitHub, Bitbucket, SonarQube, and Workday.
Contribute to internal developer portals using Backstage or similar frameworks.
Improve engineering productivity through automation, self-service capabilities, and platform standardization.
Own delivery of robust, secure, high-performance backend platforms and frontend applications.
Promote coding standards, modular design, and maintainability.
Develop extensible, plugin-based solutions and data-driven user experiences that improve developer productivity and software delivery workflows.
Define and implement unit, integration, and functional/end-to-end testing strategies.
Embed automated testing in CI/CD pipelines to enforce quality gates and prevent regressions.
Ensure systems meet correctness, reliability, and backward-compatibility requirements at scale.
Lead benchmarking, load testing, capacity planning, and other performance engineering initiatives.
Analyze and optimize responsiveness and scalability across distributed systems, and ensure applications meet performance SLAs.
Enforce secure coding practices, integrate security throughout the SDLC, and design for enterprise security, regulatory, and compliance requirements.
Partner with security teams to identify and remediate vulnerabilities.
Lead troubleshooting, root cause analysis, incident resolution, and postmortem activities for complex production issues.
Drive systemic improvements to prevent recurring incidents and improve reliability.
Lead code reviews and ensure standards for design, performance, security, and maintainability.
Mentor engineers and provide hands-on guidance on complex technical problems.
Partner with product, platform, and business stakeholders on technical roadmaps and delivery priorities.
Own cross-functional initiatives spanning frontend applications, backend services, APIs, integrations, and cloud-native architectures.
Contribute reusable frameworks, patterns, and innovations to the Software Engineering Guild.
Follow Mastercard security policies, safeguard the confidentiality and integrity of accessed information, report suspected security violations or breaches, and complete mandatory security training.

Benefits

Medical, prescription drug, dental, vision, disability, and 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, prorated based on date of hire.
10 annual paid U.S. observed holidays.
401(k) with a company match.
Deferred compensation for eligible roles.
Fitness reimbursement or on-site fitness facilities.
Tuition reimbursement eligibility.
Potential annual bonus or commissions depending on the role.