Senior Software Engineer

MastercardO'fallon, MO
$115,000 - $184,000Onsite

About The Position

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. As part of the Clearing Program within Core Payments, this role is responsible for designing, building, and operating solutions that support end-to-end clearing and settlement processing for credit and debit offline transactions. The Global Clearing Management System (GCMS) processes transaction data exchanged between acquirers and issuers, applies edits, assesses fees, and derives settlement values to ensure accurate financial reconciliation. The role plays a critical part in ensuring compliance with Mastercard processing standards, maintaining data integrity, and enabling reliable, high-volume transaction processing across global payment networks. As a Senior Software engineer, you will be responsible for development, deployment support, owning the delivery of user stories, mentoring junior team members, and performing code reviews. This is a vital role responsible for planning, developing, and coordinating all activities related to design, development, and implementation. We are seeking a highly motivated, detail-oriented, and proactive engineer who has the ability to operate under pressure in an independent, autonomous environment.

Requirements

  • Strong hands-on experience in software engineering, including development and quality engineering to design systems for reliability, performance, and scalability
  • Proven experience working with: JAVA JDK 11-17, Spring Boot, Spring Security, Maven, Hibernate / JPA, REST, and SQL Server or other object-oriented languages, front-end frameworks, and/or relational database technologies.
  • Event Driven Framework, Full APIs and JSON/SOAP based API.
  • SQL, Multi-threading, Message Queuing, & Distributed Systems.
  • Nunit/Junit or other automated unit testing frameworks.
  • Splunk alerting and monitoring solutions.
  • Unit, functional, and integration testing
  • Performance testing and engineering
  • Strong knowledge and understanding of: Cloud native developments, such as Pivotal Cloud Foundry (PCF), AWS, Etc.,
  • Software design principles (OOP, modularity, design patterns)
  • Software architecture concepts (microservices, distributed systems, scalability)
  • Data structures and algorithms
  • Experience with secure coding practices and application security principles (e.g., OWASP)
  • Ability to contribute to system design and architecture decisions

Nice To Haves

  • Domain knowledge in payments and transaction processing systems
  • Bachelor's or master's degree in computer science or equivalent experience is preferred

Responsibilities

  • Design, build, test, deploy, and maintain software components, automation frameworks, and validation tools
  • Apply strong knowledge of data structures, algorithms, and efficient coding practices in building scalable solutions
  • Contribute to end-to-end software development lifecycle, including design, development, testing, deployment, and monitoring
  • Participate in defining software architecture and design patterns to ensure scalability, reliability, and maintainability
  • Ensure systems are designed for testability, observability, performance, and operational readiness
  • Provide input into microservices and cloud migration strategies
  • Develop and implement test automation frameworks and CI/CD integration pipelines (e.g., Jenkins, XLR)
  • Design comprehensive test strategies and plans, including performance, reliability, and production simulation testing
  • Ensure high code quality and coverage using tools such as Sonar or Clover
  • Apply and promote secure coding practices, including code analysis, vulnerability detection, and mitigation strategies
  • Integrate security testing into CI/CD pipelines
  • Conduct and lead code reviews, ensuring adherence to coding standards, security practices, and maintainability
  • Act as a technical reviewer for system designs, test strategies, and implementation approaches
  • Ensure systems are observable, monitorable, and resilient across environments
  • Perform performance engineering, including load testing, tuning, and bottleneck analysis
  • Troubleshoot complex production issues and ensure rapid resolution
  • Partner with developers, architects, and product teams to drive engineering best practices
  • Mentor junior engineers and contribute to knowledge sharing across teams
  • Evaluate and recommend tools, technologies, and frameworks for continuous improvement

Benefits

  • insurance (including medical, prescription drug, dental, vision, disability, life insurance)
  • flexible spending account and health savings account
  • 16 weeks of new parent leave
  • up to 20 days of bereavement leave
  • 80 hours of Paid Sick and Safe Time
  • 25 days of vacation time
  • 5 personal days
  • 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
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