Senior Software Engineer
$115k - $184kMastercard
Senior Software Engineer
Who is Mastercard?
Mastercard is a global technology company in the payments industry. Our mission is to connect and power an inclusive, digital economy that benefits everyone, everywhere by making transactions safe, simple, smart, and accessible. Using secure data and networks, partnerships and passion, our innovations and solutions help individuals, financial institutions, governments, and businesses realize their greatest potential. Our decency quotient, or DQ, drives our culture and everything we do inside and outside of our company. With connections across more than 210 countries and territories, we are building a sustainable world that unlocks priceless possibilities for all. About the Role Join Mastercard’s Transaction Stream team in O’Fallon, MO, and help build the applications and services that power critical capabilities across the real-time payment network. This is an opportunity to work on software that operates at global scale, where speed, reliability, and resilience matter every day. As a Senior Software Engineer, you will collaborate with engineers and product partners to design, build, test, and enhance solutions that support the movement of transactions around the world. Role As a Senior Software Engineer, you will: • Design, develop, and maintain scalable test frameworks and automation solutions aligned with enterprise architecture standards• Apply software design principles and architectural patterns to create maintainable and extensible testing and validation systems
• Contribute to system architecture discussions, ensuring solutions are testable, observable, secure, and performant
• Translate business and system requirements into well-designed technical solutions, test strategies, and validation models
• Ensure secure coding practices are embedded in development and testing processes, proactively identifying vulnerabilities and risks
• Develop and execute testing strategies across all levels: unit, functional, integration, system, and performance testing
• Leverage data structures and algorithms to optimize test execution, data handling, and performance validation
• Collaborate in Agile environments, contributing to backlog refinement, sprint planning, and design discussions Responsibilities Software Engineering & Development • 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 Architecture & Design • 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 Quality Engineering & Testing • 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 Security & Compliance • Apply and promote secure coding practices, including code analysis, vulnerability detection, and mitigation strategies
• Integrate security testing into CI/CD pipelines Code Quality & Reviews • 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 Operability & Performance • 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 Collaboration & Leadership • 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 All About You • Experience building applications and REST APIs using Java, Spring Boot, and Spring Data JPA
• Strong foundation in computer science fundamentals, including data structures, algorithms, and object-oriented design
• Ability to write clean, secure, testable code and contribute to unit, service, and integration testing.
• Comfort working with SQL and relational data concepts.
• Strong analytical and problem-solving skills, with the ability to debug issues and identify practical solutions.
• Strong verbal and written communication skills and the ability to work effectively in a collaborative team environment.
• Self-motivated, organized, and eager to learn, with a passion for continuous improvement and delivering results.
• Strong hands-on experience in software engineering, including development and quality engineering
• Proven experience working with:
• Testing across platforms: Linux and web applications
• Automation development and CI/CD integration and deployment (Jenkins / XLR) and code coverage tools (Sonar, Clover) to ensure high code/ conditional coverage
• Unit, functional, and integration testing
• Performance testing and engineering
• Strong knowledge and understanding of:
• 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 Preferred Qualifications • Experience in cloud and microservices architecture or mainframe modernization
• Experience designing systems for reliability, performance, and scalability
• Domain knowledge in payments and transaction processing systems
• Bachelor’s or master's degree in computer science or equivalent experience is preferred
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 us.fitly.work 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 RangesO'Fallon, Missouri: $115,000 - $184,000 USD
- ...of web applications, system to system interfaces and complete software solutions. Design and develop test automation scenarios to validate... ...of automation code where needed. Work closely with software engineers to build quality in, ensuring proper test and requirement...Senior
- ...Developer Work with a talented team of developers and test engineers to develop fraud management applications. This position will be... ..., etc. Excellent technical acumen and ability to learn new software quickly. Strong knowledge of traditional testing...Senior
- ...Job TitleBachelor’s degree in information systems, information technology, computer science, engineering, or equivalent work experience.More than 7 years of industry experience.Excellent communication skills, with the ability to interact across multiple organizational...SeniorWork experience placement
- ...Senior Software EngineerLocation: O'Fallon, Missouri - onsite (LOCAL ONLY)Rate - $65/hr. on C2CJava/JEE6-10 yearsEssential responsibilities... ...and design activities collaborating with other Engineers & Engineering Team.Ability to work with existing and evolve services...SeniorWork experience placementInternshipLocal area
$115k - $184k
...Senior Software EngineerMastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our... ...Authorization payment network. This position is on the performance engineering team that partners with development teams on optimization...SeniorFull timePart timeWorldwideFlexible hours$115k - $184k
...Senior Software Engineer - Java Full Stack EngineerMastercard 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...SeniorFull timePart timeWork experience placementWorldwideFlexible hours- ...Sr. Software Development EngineerLocation: O'fallon, MODuration: 12+ monthsPrimary Skills:C# developmentFront end/angularAPIDesired Skills:SQLBatchRole:Plan, design and develop technical solutions and alternatives to meet business requirements in adherence with MasterCard...Senior
$115k - $184k
...products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior Software Engineer Overview Customer Connectivity is a global Mastercard team that designs, builds and supports service platforms that...SeniorFull timePart timeWork experience placementWorldwideFlexible hours$115k - $184k
...products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior Software Engineer Who is Mastercard? We work to connect and power an inclusive, digital economy that benefits everyone, everywhere, by...SeniorFull timeContract workPart timeWork experience placementWorldwideFlexible hours$115k - $184k
...products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior Software Engineer Who We Are Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with...SeniorFull timePart timeWorldwideFlexible hours$115k - $184k
...products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior Software Engineer Who is Mastercard? Mastercard is a global technology company in the payments industry. Our mission is to connect and...SeniorFull timePart timeWorldwideFlexible hours$115k - $184k
...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...SeniorFull timePart timeWork experience placementWorldwideFlexible hours$115k - $184k
...products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior Software Engineer Overview: Mastercard Send (part of the Mastercard Move portfolio) enables near real-time money movement across billions...SeniorFull timePart timeWorldwideFlexible hoursShift work$115k - $184k
...products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior Software Development Engineer Overview The Senior Software Development Engineer is a senior individual contributor responsible for designing,...SeniorFull timePart timeWorldwideFlexible hours$126.65k - $171.35k
Software Engineer-Developer, Phantom Works Weapons (Experienced or Senior)Company:The Boeing CompanyThe Boeing Company is seeking an Application Software Engineer (Experienced or Senior) to join the Phantom Works Weapons team in St. Charles, MO (St. Louis Area). This teamsupports...SeniorPermanent employmentFull timeWork experience placementCurrently hiringRelocationVisa sponsorshipWork visaRelocation packageFlexible hoursShift work- ...Senior Software EngineerSeeks a Senior Software Engineer who will be a crucial part of our software team. The selected candidate will have to write scalable, robust, and easy-to-maintain code, and will be required to translate software requirements into high-performance...SeniorWork experience placement
- ...Sr. Software EngineerLocation: O'Fallon, MOJob Summary: We are seeking a skilled Software Developer with a strong background in Java, Spring Boot, Microservices, and Kafka. The ideal candidate will have a minimum of 5 years of experience in software development, with...Senior
$115k - $184k
...products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior Software Engineer– RPPS Platform Who is Mastercard? Mastercard powers economies and empowers people in more than 200 countries and territories...SeniorFull timePart timeRemote workWorldwideFlexible hours- ...multi-tiered web applicationsExperience integrating vendor and open source products into an overall systemExperience specifying hardware/software requirements, and estimating complex IT effortsSelf-motivated with the ability to accomplish tasks with minimal direction...Senior
- ...Software DeveloperThe Commercial Solutions team is engaged in working with new and innovative... ...Development Best Practices.Assist Senior Team members in modification of the documentation... ...:3 - 5 years experience in the software engineering fieldKnowledge of common industry...SeniorWork experience placement
- ...realize their greatest potential. Title and Summary Senior Site Reliability Engineer Overview-The ProCOM team is looking for a Site... ...• Support the application CI/CD pipeline for promoting software into higher environments through validation and operational...SeniorFull timePart timeImmediate startWorldwideFlexible hours
- ...Senior Java Engineer Senior Java Engineer O’Fallon MO – Day 1 Onsite BS in CS 10+ yrs. experience Experience in object-oriented programming and concepts. Experienced in Java backend application development. Comfortable enough in handling algorithms,...Senior
- ...Software EngineerInterview: Coding Test + F2F This is hybrid from day-1 (Need only local candidates) Visa: USC, GC, GC EAD, H4, L2Responsible... ...in interacting with Product ownersUnderstands operational and engineering experience, actively works to improve experience and metrics...SeniorContract workLocal area
- Mastercard is seeking a Senior Site Reliability Engineer to enhance reliability, scalability, and performance of our critical IT & Data Management platforms. You will design resilient architectures, automate deployments, and champion observability to ensure always-on services...Senior
$60k - $135k
...Senior Java DeveloperWe are seeking a highly skilled Java Developer with strong experience in building enterprise-grade, cloud-native applications. The ideal candidate should have hands-on expertise in Java, Spring Boot, REST APIs, Microservices Architecture, Cloud Platforms...SeniorMinimum wageLocal area- As a Senior Site Reliability Engineer at Mastercard, you’ll drive the performance, reliability, and scalability of mission-critical, cloud-native payment... ...across distributed systems. Collaborating closely with software and platform teams, you’ll champion SRE best practices,...Senior
- Mastercard seeks a Senior Site Reliability Engineer in Financial Services within the IT & Data Management team. You’ll design, build, and optimize... ...scalable platforms that power global payments. Partner with software and data teams to improve reliability, observability, and...Senior
$96k - $163k
...governments realize their greatest potential. Title and Summary Senior Site Reliability Engineer Who is Mastercard? At Mastercard technology, we... ...our developers during the application build phase in software run principles that include operational design,...SeniorFull timePart timeWorldwideFlexible hours$96k - $163k
...algorithms, data structures, scripting, pipeline management, and software design principles. Systematic problem-solving... ...digital payment solutions. We are currently searching for a Senior Site Reliability Engineer to join our Foundry BizOps team. This role is pivotal in...SeniorFull time$115k - $184k
...of products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior AI Engineer Overview The Security Solutions Data Science team develops AI and machine learning capabilities that help protect the global...SeniorFull timePart timeWorldwideFlexible hours
Do you want to receive more vacancies?
Subscribe and receive similar vacancies to Senior Software Engineer. Be the first to apply!
- cybersecurity software engineer O Fallon, MO
- software developer fintech O Fallon, MO
- senior robotics software engineer O Fallon, MO
- part time software developer O Fallon, MO
- part time software developer remote O Fallon, MO
- software engineer part time O Fallon, MO
- software engineer full time O Fallon, MO
- entry level software engineer remote O Fallon, MO
- senior software engineer ruby on rails O Fallon, MO
- consulting software engineer O Fallon, MO




