Mastercard · O'Fallon, Missouri, US

Software Engineer I

OpenFull-timePay not stated

Open — Mastercard has a posting for this job. Posted 7 Oct 2026.

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Posted 7 Oct 2026 · Full-time · Pay not stated

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About this job

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

Software Engineer I

About the Role

Join Mastercard’s Transaction Stream team in O’Fallon, Missouri, 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 on a global scale, where speed, reliability, and resilience matter every day. As a Software Engineer I, you will collaborate with engineers and product partners to build, test, and enhance solutions that support the movement of transactions around the world.

Role and Responsibilities

Develop, test, maintain, and support software applications and services with guidance from experienced engineers

Write clean, maintainable, reusable, and secure code following established engineering standards, software design principles, and best practices

Participate in software design activities by translating functional and non-functional requirements into scalable, maintainable, and secure software components and services

Contribute to the implementation of established software architecture patterns and system designs while gaining experience with scalability, reliability, security, and long-term maintainability considerations

Develop and maintain unit, functional, and integration tests to ensure software quality, reliability, and correct system behavior

Apply knowledge of data structures, algorithms, and software engineering fundamentals to develop efficient and scalable software solutions

Participate in code reviews and incorporate feedback to improve code quality, maintainability, and engineering practices

Contribute to APIs, microservices, distributed applications, and event-driven solutions.

Apply secure coding practices and security-by-design principles throughout the software development lifecycle

Collaborate with Product, QA, Architecture, Security, DevOps, and Operations teams to deliver software solutions that meet business and technical requirements

Support cloud-based applications and services while assisting with monitoring, troubleshooting, root cause analysis, and issue resolution

Assist in monitoring, analyzing, and optimizing application performance, scalability, and resource utilization to meet business and operational requirements

Contribute to CI/CD, automation, observability, reliability, performance, and operational excellence initiatives

Help implement operational readiness practices, including logging, monitoring, alerting, and system supportability considerations

Continuously learn and adopt modern software engineering technologies, tools, and practices

All About You

Bachelor's degree in computer science, engineering, information technology, or a related field, or equivalent practical experience in Software Development through a relevant internship, Co-Op, research, or professional business is preferred.

Strong understanding of programming fundamentals, data structures, algorithms, and object-oriented design concepts.

Knowledge of software design principles and the ability to develop maintainable, scalable, and reusable software solutions.

Understanding common architectural concepts and patterns such as layered architectures, microservices, event-driven systems, and distributed applications.

Working knowledge of Java, Golang, Kotlin, C#, or similar programming languages.

Familiarity with Spring Boot, Spring, Hibernate, or similar frameworks.

Exposure to JavaScript, Angular, or similar front-end technologies is a plus.

Understanding REST APIs, microservices, relational databases, SQL, and software testing practices.

Familiarity with unit testing frameworks and automated testing methodologies.

Familiarity with Git, CI/CD pipelines, cloud platforms, DevOps practices, and Agile software development methodologies.

Basic understanding of application performance, scalability, monitoring, and observability concepts.

Understanding troubleshooting methodologies, root cause analysis, and problem-solving techniques.

Basic understanding of secure coding principles, OWASP guidelines, and application security best practices.

Strong analytical thinking, problem-solving, communication, collaboration, and continuous learning skills.

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 reasonable_accommodation@mastercard.com 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. THIS POSTING RELECTS ONE OR MORE CURRENT VACANCIES ON OUR TEAM, AND MASTERCARD INTENDS TO FILL THIS POSITION BY 01/05/2027. If the fill date has passed, Mastercard intends to fill this position as soon as possible.

Pay Ranges

O'Fallon, Missouri: $72,000 - $115,000 USD

Read the full posting

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  • Other posting · Req OFallon-Missouri · Posted 5 Oct 2026

    Pay not stated

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  • Other posting · Req OFallon-Missouri · Posted 14 Sep 2026

    Pay not stated

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If the main posting closes, the newest of these takes its place and this page stays open.

Not this job's pay

What do Corporate – Information Technology jobs in Missouri pay?

Talentify has no pay figure for this posting. The lines below are about Corporate – Information Technology jobs on Talentify in Missouri as a group, computed by Talentify's job index across their postings. They are not the pay for this job.

Of the 146 Corporate – Information Technology jobs on Talentify in Missouri, 17 list pay per year.

Taking the midpoint of each listed range, the middle half pay 85,000–112,500 USD per year and the median is 100,000 USD per year.

12 of these 17 name no currency; they are counted as USD because the jobs are in the United States.

Pay as employers listed it, not adjusted or verified. Updated 2026-11-07.

Computed on 2026-11-07 from the pay in 17 listings.

Not this job's pay

U.S. Bureau of Labor Statistics, for Software Developers, the occupation this job title matches. It describes the occupation, not this job.

The median wage for Software Developers in Missouri was 60.64 USD per hour (126,120 USD per year) in May 2025; the middle half earned 46.89–74.52 USD per hour.

U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics, May 2025

Software Engineer pay and outlook in Missouri

Also open

Also open at Mastercard

Mastercard's other jobs that have a page here. Each page says open or closed for itself.

Same job, other employers

Software Engineer jobs in Missouri at other employers

Pages on Talentify for this job in Missouri, at employers other than Mastercard. Each page says open or closed for itself.