At a glance
Mastercard is hiring a Principal Software Engineer in O'Fallon, MO. It is a full-time role in Software & IT, first listed on November 1. The advertised pay is $170,000–$281,000 a year. The description mentions Agile, Java, Azure, AWS, Generative AI and Microservices. Mastercard has 99 other openings in the US, 36 of them in O'Fallon, MO. Across all employers on USA Jobs 24 there are 17 Software & IT openings in O'Fallon, MO today; the typical one asks for 6 years and advertises about $165,000 a year at the midpoint.
AgileJavaAzureAWSGenerative AIMicroservicesREST APIsData modelling
About this role
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
Principal Software EngineerPrincipal Software EngineerOverview
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 (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.
Department Overview
At Mastercard Labs / Foundry, we empower innovation by exploring emerging technologies and building cutting-edge solutions that shape the future of commerce. Develop highly scalable world class solutions from inception to execution, accelerate technology evaluation and adoption.
Role Summary
As a Principal Software Engineer, you will:
• Collaborate with stakeholders across Product, Technical, Business Operations, and other Mastercard teams to understand product requirements and lead the design and architecture of scalable solutions.
• Design software architecture in alignment with Mastercard standards and present solutions to the Solution Architecture Board for approval.
• Develop and support application software in adherence to Mastercard’s standards, processes, and best practices.
• Deliver high-quality, secure, and scalable software solutions aligned with the product roadmap, within time and budget constraints.
• Research and evaluate technical solution alternatives to meet business needs.
• Create and maintain system and testing documentation per departmental standards.
• Ensure compliance with audit requirements and Mastercard’s QA/QC processes.
• Modernize and simplify existing architectures to enhance scalability, performance, and operational efficiency.
• Champion engineering excellence through hands-on contributions and collaborative leadership.
• Support the collection and reporting of project and software metrics.
• Mentor and coach team members to foster engineering leadership.
All About You
Required Qualifications:
• Bachelor’s degree in Information Technology, Computer Science, or a related field.
• Extensive software development experience with a strong track record of delivering enterprise-grade solutions.
• Desired strong knowledge of card ecosystem including, Loyalty, Clearing, Fraud, Disputes, Issuer, Acquirer & Merchant domains.
• Deep understanding of software engineering concepts, methodologies, and Agile/SAFe Agile practices.
• Proven expertise in software architecture, design, and application development.
• Strong communication skills (verbal and written) and the ability to quickly learn and apply new technologies and frameworks.
• High energy, detail-oriented, proactive, and capable of working under pressure to meet deadlines.
• Strong collaboration and organizational skills with a high degree of initiative and self-motivation.
• Ability to work effectively in a matrixed, geographically distributed team environment.
• Excellent troubleshooting skills and a proactive approach to problem-solving.
• Experience building high-performing, secure applications with a strong grasp of architecture, performance, and security principles.
• Proficiency in Java-based systems and services, cloud technologies (Azure/AWS), AI/ML, Gen AI and microservices architecture.
• Expertise in Spring, RESTful services, API design principles, and best practices.
• Familiarity with data modeling, database design, data warehousing, Oracle, Redis, and reporting technologies.
• Strong knowledge of Mastercard privacy by design
• Knowledge of enterprise-level application frameworks and tools.
Big Data & Analytics Expertise:
• Experience designing and architecting high-volume data systems using technologies such as Hadoop, Snowflake, Databricks, and other modern data platforms.
• Strong understanding of data pipelines, ETL/ELT processes, and distributed data processing frameworks (e.g., Spark, Hive).
• Ability to build scalable, fault-tolerant data architectures that support real-time and batch analytics.
• Familiarity with data governance, data quality, and security best practices in large-scale data environments.
Preferred Qualifications:
• Experience in the Core payments, Loyalty, Fraud domains.
• Passion for building innovative solutions that positively impact global payments.
• Data-savvy mindset with an understanding of how data enhances convenience and security in payments.
• Clear mission focus aligned with business objectives and team success.
• Strong stakeholder management and expectation-setting skills.
• Confident communicator with the ability to articulate technology vision and roadmaps to diverse audiences.
• Problem-solver with a results-driven mindset.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.
Pay Ranges
O'Fallon, Missouri: $170,000 - $281,000 USDUSA Jobs 24 copied this listing from Mastercard's official careers site on November 1, 2026 and checked it again November 2, 5:17 AM ET. Mastercard will never ask you to pay to apply or to buy equipment with a check they send you. If anyone does, it is a scam.
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