Software Engineer II

Mastercard • O'fallon, MO

2d • $92,000 - $147,000

About The Position

Join Mastercard’s Core Payments, Network Solutions team to develop software supporting secure, reliable, and scalable payment-processing capabilities. The role combines software development, quality engineering, and operational readiness to deliver dependable solutions across the payments ecosystem.

The Software Engineer II designs, builds, tests, deploys, and maintains software components, automation frameworks, and validation tools for payment applications and services. The role applies engineering fundamentals to system interactions, transaction-processing workflows, performance, and resilience. The engineer independently executes routine and moderately complex assignments, with occasional guidance on unfamiliar or highly complex work.

The position works across the software development lifecycle, including design, implementation, testing, deployment, monitoring, and maintenance. It contributes to architecture discussions, test strategies, secure engineering, performance and operational excellence, and collaboration with engineering, architecture, product, and operations stakeholders.

Requirements

• Demonstrated software development and quality engineering experience, including building microservices with Java and Spring Boot.
• Proficiency with relational data concepts and SQL databases, preferably PostgreSQL and Oracle SQL.
• Strong understanding of cloud-native architecture, including AWS, PCF, and Kubernetes, as well as microservices, distributed-systems, and event-driven design concepts.
• Knowledge of object-oriented programming, modularity, software design patterns, data structures, and algorithms.
• Ability to apply domain-driven design and contribute to system design decisions using patterns such as MVC, API Gateway, Dependency Injection, Lazy Loading, service-to-worker, and Intercepting Filter.
• Understanding of mission-critical engineering principles for payment applications, including security, scalability, resilience, customer experience, testing, operability, and simplification.
• Ability to develop and execute unit, functional, integration, and performance tests across Linux and web applications.
• Experience developing test automation and integrating testing, code coverage, and deployment into CI/CD pipelines using tools such as Jenkins, XL Release (XLR), GitHub Actions, Sonar, and Clover.
• Knowledge of secure coding and application security principles such as OWASP, and participation in peer code reviews.
• Ability to configure code-quality checks, vulnerability scanning, and software composition analysis using tools such as Sonar, Zally, Checkmarx, JFrog Xray, and Veracode.
• Ability to orchestrate release workflows, use standardized pipelines through APIs, and manage builds and artifacts with tools such as Artifactory, including canary or blue-green deployments.
• Strong analytical, debugging, and problem-solving skills, including performance analysis and production troubleshooting using Splunk.
• Clear verbal and written communication and effective collaboration with engineering and product partners.
• Responsible for following Mastercard security policies and practices, preserving the confidentiality and integrity of accessed information, reporting suspected security violations or breaches, and completing required security training.

Nice To Haves

• Experience in cloud and microservices architecture or mainframe modernization.
• Experience designing systems for reliability, performance, and scalability.
• Domain knowledge of payment networks, transaction-processing workflows, or integrations between payment systems.
• Bachelor’s or master’s degree in Computer Science, or equivalent practical experience.

Responsibilities

• Design, build, test, deploy, and maintain software components, automation frameworks, and validation tools supporting Core Payments and Network Solutions applications and services.
• Develop microservices using Java and Spring Boot and work with relational SQL databases.
• Apply data structures, algorithms, and efficient coding practices to build scalable solutions.
• Contribute across the software development lifecycle, including deployment, monitoring, and ongoing maintenance.
• Participate in software design and architecture discussions and apply established patterns to support scalability, reliability, and maintainability.
• Apply domain-driven design principles to translate payment-processing requirements and service interactions into maintainable software solutions.
• Design components for testability, observability, performance, and operational readiness, and contribute to microservices and cloud migration approaches.
• Develop and maintain unit, functional, and integration tests, automation frameworks, and CI/CD testing integrations.
• Contribute to test strategies and plans covering transaction-processing workflows, service integrations, performance, reliability, and production simulation.
• Use code analysis and coverage tools to identify quality issues, anti-patterns, and testing gaps.
• Apply secure coding standards and integrate security testing, vulnerability scanning, and software composition analysis into delivery pipelines.
• Participate in peer code reviews and technical reviews of designs, test strategies, and implementation approaches.
• Analyze and improve transaction-processing performance, response times, and scalability through load testing, tuning, and bottleneck analysis.
• Support observability, monitoring, resilience, and operational readiness across environments.
• Diagnose production issues, identify root causes, and implement practical solutions, seeking guidance on unfamiliar or highly complex scenarios.
• Manage release workflows, builds, and artifacts through standardized CI/CD pipelines, including canary or blue-green deployment techniques.
• Partner with engineering, architecture, product, and operational stakeholders to deliver payment solutions and strengthen engineering practices.
• Share knowledge and support colleagues through collaborative problem-solving and peer feedback.
• Evaluate tools, technologies, and frameworks and recommend opportunities for continuous improvement.
• Communicate clearly and work effectively within a collaborative team environment.
• Meet first-year success measures by delivering assigned software components from design through maintenance, producing secure and maintainable code, strengthening testing and release processes, improving performance and reliability, resolving issues, and collaborating with partners.

Benefits

• Insurance, including 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.
• Eligibility for tuition reimbursement.

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: No Education Listed