Internship Java Developer Jobs in Saint Louis, MO

Over the course of this 18-month program, you'll build specialized expertise through hands‑on experience, structured learning, and mentorship from industry leaders. You'll work on real business challenges, applying your skills to projects that create meaningful impact. Along the way, you'll deepen your knowledge of Mastercard's business, collaborate with teams across the organization, and develop the technical, analytical, and professional capabilities needed to accelerate your career. By the end of the program, you’ll have a strong foundation in your chosen field and the confidence to continue to grow here at Mastercard.

Mastercard’s Software Engineering teams design, build, and optimize high‑performing, highly scalable software solutions and products for some of the world's top brands. Using advanced cloud platforms, AI frameworks, and secure blockchain technologies, your work will transcend borders, connecting communities and transforming commerce.

As a Software Engineer, you will begin your career building real‑world software solutions that support secure, scalable, and high‑performing technology platforms. This role is designed for individuals who are excited to learn, grow, and apply software engineering skills in a collaborative environment. You will work alongside experienced engineers, receive structured onboarding and mentorship, and contribute to projects that impact customers globally.

You may:

• Write clean, maintainable code following established standards and best practices
• Contribute to design, development, testing, and deployment of software features
• Write basic automated tests to validate expected behavior and quality
• Apply secure coding practices and defensive programming techniques
• Participate in code reviews and incorporate feedback
• Use debugging tools, logs, and documentation to help identify and resolve issues
• Learn and work with existing systems, tools, and development workflows

Note: responsibilities, projects, tools, technologies and programming languages will vary by team

• Currently enrolled a Bachelor’s or accelerated Master’s degree in Computer Science, Engineering, or a related field graduating between Dec 2026 – June 2027
• Project-based experience (academic, internship, or personal) using one or more programming languages such as Java, JavaScript, Python, or C#
• Advancedproficiencyin data structures, algorithms, and core computer science concepts
• Familiarity with version control tools (e.g., Git)
• Experience or coursework involving automated testing
• Strong problem-solving skills and eagerness to learn

This role is not eligible for Mastercard’s work authorization sponsorship. As such, candidates must be eligible to work in the United States, now as well as in the future, without employer sponsorship. For example, students or recent graduates in the United States on an F1 visa (including those with CPT or OPT authorization) are not eligible for this role.

National Salary Range (Applies Regardless of Location): $100,000–$130,000

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.

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.

• 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

• 56 hours of Paid Sick and Safe Time
• jury duty leave
• and on-site fitness facilities in some locations

Everyone wants easier ways to pay; we invent them. Checkout lines are slow; we speed them along. Merchants want more sales; we give them data and insights. People need financial access; we connect them. Corporate purchasing is complicated; we make it simple. Commuters are busy; we speed them on their way. Governments need greater efficiencies; we help create them. Small businesses are virtual; we give them access to a world of buyers. Retailers want to fight fraud; we provide the tools.