Principal AI Engineer

Mastercard; Toronto; On-site; CAD 120,000 - 160,000; Full time

Job summary

A global technology leader in payments is seeking a Principal AI Engineer to architect and deliver AI-powered platforms. The role emphasizes designing robust systems using innovative AI tools and collaborating with cross-functional teams to advance Mastercard’s AI strategy. Candidates should have experience in AI/ML system design, proficiency in Python, and a commitment to ethical AI development. Join us to shape the future of AI in global commerce.

Qualifications

• Proven experience designing and deploying AI/ML systems at scale, with expertise in LLMs and generative AI.
• Excellent communication and collaboration skills, with a track record of influencing teams.

Responsibilities

• Design and implement advanced AI agents and supporting infrastructure.
• Partner with engineers, data scientists, and product teams to define technical strategy.
• Lead testing and evaluation of LLMs and emerging AI technologies.
• Develop and refine prompt strategies to maximize LLM performance.
• Architect safeguards to ensure compliance and ethical standards.
• Build scalable APIs and microservices integrating AI features.

Skills

AI/ML system design

Python

RESTful APIs

Cloud platforms

AI safety

Prompt engineering

Tools

FastAPI

Flask

Node.js

Job description

Our Purpose

Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we’re helping build asustainableeconomy where everyone can prosper. We support a wide range of digital payments choices, making transactionssecure, 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 AI Engineer About Mastercard Mastercard is a global technology leader in the payments industry, connecting billions of consumers, financial institutions, merchants, governments, and businesses worldwide. We are shaping the future of commerce by enabling secure, seamless, and intelligent transactions. Artificial Intelligence is central to our strategy—making Mastercard stronger and commerce safer, smarter, and more personal.

Role Overview: As a Principal AI Software Engineer, you will play a pivotal role in architecting and delivering next-generation AI-powered platforms that drive innovation and scale across Mastercard. You will lead by example—designing and building intelligent systems using cutting-edge AI tools, large language models (LLMs), and emerging frameworks. While this is an individual contributor role, you will collaborate deeply with cross-functional teams, mentor engineers, and influence technical direction across the organization.

You will be responsible for developing Agentic AI systems, designing robust backend services, and driving experimentation with novel AI capabilities. Your work will directly impact Mastercard’s ability to deliver secure, scalable, and ethical AI solutions.

Responsibilities

• Architect & Build Agentic AI Systems- Design and implement advanced AI agents and supporting infrastructure that power Mastercard’s AI platform.
• Technical Leadership & Collaboration- Partner with senior engineers, data scientists, and product teams to define technical strategy, share best practices, and drive alignment across initiatives.
• AI Experimentation & Evaluation- Lead rigorous testing and evaluation of LLMs, emerging AI technologies, and frameworks to identify opportunities for innovation and improvement.
• Prompt Engineering & Optimization- Develop and refine prompt strategies to maximize performance, reliability, and contextual accuracy of LLM-based systems.
• Guardrail & Safety Design- Architect and implement safeguards to ensure AI outputs are secure, compliant, and aligned with Mastercard’s ethical standards.
• Backend Engineering Excellence- Build scalable APIs, microservices, and data pipelines that integrate seamlessly with AI-powered features.
• Continuous Learning – Stay current with the latest developments in AI, LLMs, and software engineering best practices.

All About You – Qualifications

• Proven experience designing and deploying AI/ML systems at scale, with deep expertise in LLMs and generative AI.
• Advanced proficiency in Python and backend frameworks (e.g., FastAPI, Flask, Node.js).
• Strong understanding of RESTful APIs, microservices architecture, and cloud platforms (Azure preferred; AWS or GCP also valued).
• Demonstrated ability to lead complex technical initiatives while remaining hands-on with code.
• Passion for AI safety, prompt engineering, and ethical AI development.
• Excellent communication and collaboration skills, with a track record of influencing across teams and disciplines.
• Commitment to staying current with the latest AI research, tools, and engineering practices.

Why Join Us

At Mastercard, you’ll help shape the future of AI in global commerce—solving complex challenges at scale, driving financial inclusion, and reinforcing the trust and security that define our brand. You’ll work with world-class talent, cutting-edge technologies, and will make a lasting impact.

#AI1 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 [e-mail] 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.