Software Engineer Intern Jobs in High Ridge, MO (NOW HIRING)

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 II
Overview
The Mastercard Authentication Program owns how consumer authentication works across both in-store and e-commerce use cases. This role contributes to building and operating best-in-class authentication products such as ID Check, Token Authentication Service, and Token Authentication Framework, driving adoption, scale, and revenue growth.
This position sits at the intersection of Site Reliability Engineering, platform engineering, and release engineering, ensuring our platforms are scalable, resilient, secure, and production-ready across hybrid environments (Kubernetes, cloud, and on-prem).
As a Software Engineer II, you will contribute to building scalable backend services using Java/Spring and modern user interfaces using Angular and Node.js within a distributed architecture. You will support end-to-end delivery including solution design, development, testing, deployment, and production support while adhering to engineering best practices for code quality, security, performance, and reliability. Working closely with cross-functional teams, you will help deliver production-grade solutions and continuously improve your skills across cloud platforms, DevOps practices, observability, and software architecture. You will also leverage AI-assisted development tools to enhance productivity and support multiple phases of the software development lifecycle.
Role
In this role, you will:
• Design, develop, and own Java-based backend services and REST APIs in a distributed architecture.
• Build and enhance UI applications using Angular and Node.js.
• Own end-to-end delivery including solution design, development, testing, deployment, configuration, documentation, and operational support.
• Participate in technical design sessions, architectural reviews, and solution planning to help deliver scalable, resilient, secure, and maintainable software solutions.
• Ensure high-quality code through peer code reviews, automated testing, and adherence to engineering standards and best practices.
• Design, develop, and maintain unit, functional, and integration tests to ensure software quality and reliability.
• Apply secure coding standards and security best practices throughout the software development lifecycle, proactively identifying and remediating vulnerabilities.
• Drive engineering best practices including clean architecture, performance optimization, resiliency, scalability, and observability.
• Analyze application and system performance, identifying opportunities for optimization and scalability improvements.
• Troubleshoot complex production issues, perform root cause analysis, and implement corrective actions to improve platform stability and operational excellence.
• Collaborate with cross-functional teams to deliver high-quality software solutions that meet business and customer needs.
All About You
Requirements
• Strong hands-on experience in Java, Spring Boot, and REST APIs.
• Hands-on experience with Angular (2+) and Node.js.
• Experience building and maintaining scalable, production-grade applications.
• Strong problem-solving, troubleshooting, and debugging skills in distributed systems.
• Solid understanding of software design principles, object-oriented programming, and software engineering best practices.
• Understanding of software architecture concepts, design patterns, and scalable distributed application design.
• Experience designing and executing unit, functional, and integration testing strategies.
• Understanding of data structures, algorithms, and their application in building efficient, scalable software solutions.
• Knowledge of secure coding principles, application security fundamentals, and vulnerability prevention techniques.
• Experience performing code reviews and contributing to engineering quality standards.
• Strong communication skills and the ability to collaborate effectively across teams.
Preferred Qualifications
• 3-5 years of software engineering experience.
• Experience with cloud platforms such as Kubernetes, AWS, Azure, or PCF.
• Exposure to CI/CD pipelines, automation, and DevOps engineering practices.
• Experience with observability platforms, monitoring, logging, and operational support practices.
• Exposure to performance testing, application tuning, and capacity planning.
• Experience using AI-assisted development tools throughout the software development lifecycle.
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.
Pay Ranges
O'Fallon, Missouri: $92,000 - $147,000 USD