AI Engineer ||

Location: O'Fallon, Missouri

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

Role Summary

The AI Engineer is responsible for designing and delivering AI-powered solutions that improve engineering productivity and business workflows. This role requires a strong foundation in AI/ML concepts, with hands-on expertise in LLM systems, data preparation, and context design (including chunking) to build scalable, high-quality AI solutions.

What You Will Do

Lead AI-Driven Solution Development

• Identify and drive high-impact AI use cases across engineering and business workflows
• Design end-to-end AI solutions leveraging LLMs, orchestration, and automation
• Move rapidly from exploration to production-grade implementations

Build LLM Solutions & Intelligent Agents

• Develop LLM-based applications including prompt frameworks, orchestration layers, and integrations
• Create and evolve AI-powered agents (e.g., Copilot-based or similar) for workflow automation and decision support
• Apply techniques such as retrieval-augmented approaches, context management, and prompt optimization
• Design Data, Context & Chunking Strategies (Critical)
• Structure and prepare data for LLM consumption, including effective chunking and context window optimization
• Design retrieval strategies that improve relevance, accuracy, and response quality
• Balance context size, latency, and cost while maintaining solution effectiveness

Apply Strong AI/ML Foundations

• Understand and reason about model behavior, evaluation, bias, and limitations
• Tune and adapt prompts, context, and workflows instead of relying on model retraining
• Ensure responsible and effective use of AI through sound engineering practices
• Drive Engineering Productivity with AI
• Apply AI tools (e.g., Copilot and similar) to improve developer velocity and quality
• Build reusable patterns for AI-assisted coding, testing, and documentation
• Measure and scale productivity impact across teams

Data & Application Engineering

• Build data pipelines and integrations to support AI workflows
• Develop APIs, services, and applications embedding AI capabilities
• Ensure solutions are scalable, maintainable, and integrated into real workflows

What You Bring

Strong foundation in AI/ML concepts, especially LLMs and modern AI systems

Hands-on experience with

Prompt engineering and LLM orchestration frameworks

Context design, chunking strategies, and retrieval techniques

Working with structured and unstructured data for AI use cases

Solid software engineering and system design experience

Ability to build end-to-end AI solutions (data → context → LLM → application)

Pragmatic mindset focused on quality, usability, and business impact

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 [email protected] 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

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 02/02/2027. If the fill date has passed, Mastercard intends to fill this position as soon as possible.

Pay Ranges

O'Fallon, Missouri: $92,000 - $147,000 USD