Senior AI Engineer II in Burgess Hill

The Enterprise Technology Services organization partners with every part of the American Express business to power the company’s growth and innovation with trust and efficiency, and drive competitive differentiation with speed. We support the delivery and operations of technology, digital, and data capabilities, platforms, and services globally. Specifically, our team is responsible for the company’s technology engineering, architecture, and infrastructure, providing 24x7 support to ensure an uninterrupted, high-quality experience for customers and colleagues.

At American Express, AI is reshaping the future of commerce and redefining the experiences our commercial customers and card members expect. Within Amex Technology, we are building platforms, products, and governance that enable agentic AI systems to operate responsibly and at scale across the enterprise. Our focus is on agentic AI development: designing intelligent, adaptive systems that can plan, reason, and act across complex workflows with appropriate levels of autonomy. These systems power autonomous workflows, decision support, and customer-facing experiences—while meeting the high standards for security, explainability, reliability, and compliance required in financial services.

As a Senior AI Engineer – Agentic AI, you will be a core builder responsible for turning complex, ambiguous problems into production‑grade agentic systems that operate on real financial data, serve real customers, and meet real regulatory requirements. You will work end to end: shaping solutions with product and design, building and shipping production code, and owning what you deliver after launch. The scope of this role spans customer-facing LLM‑powered features, agentic systems that automate financial workflows, and internal AI capabilities that enable other engineers to build with AI safely and efficiently. This is not a research-only role. We are looking for engineers who are comfortable operating with autonomy, exercising sound judgment, and pushing the technical envelope within the realities of a regulated financial environment.

Technical Environment

• Languages: Python, Go, TypeScript
• Cloud and infrastructure: AWS and/or GCP, Kubernetes
• APIs and services: REST, gRPC
• Distributed systems: event‑driven architectures, including Kafka
• Agentic AI and ML
• Commercial and open‑source LLMs integrated into agentic workflows
• Tooling for agent orchestration, retrieval‑augmented generation, vector storage, and evaluation
• Strong schema, validation, and state management practices
• AI-assisted development
• Fluency with AI‑assisted and agentic development workflows for design, implementation, testing, debugging, and refactoring

All systems are built to meet high standards for reliability, security, and auditability, reflecting the responsibility of deploying autonomous AI in a financial services environment.

Responsibilities

• Design, build, and ship LLM‑powered and agentic product features that change how customers manage their finances.
• Build agentic AI systems that reason over context, invoke tools, take real actions, and recover gracefully from failure.
• Architect and implement production‑grade RAG pipelines over sensitive financial data, with strict requirements for correctness, auditability, and safety.
• Contribute to shared AI infrastructure, including LLM services, agent orchestration frameworks, and evaluation and monitoring tooling, that scales agentic development across Amex Technology.
• Own the systems you build in production, including reliability, latency, cost, and failure modes.
• Work closely with product and design partners; engineers in this role are expected to think in terms of customer outcomes, not just technical execution.

Minimum Qualifications

• Proven software engineering experience, including meaningful production experience with LLMs or applied ML systems.
• A track record of shipping AI‑powered or agentic systems that real users depend on.
• Strong engineering fundamentals across backend systems, APIs, data pipelines, and cloud infrastructure.
• Hands‑on experience with modern LLM tooling and agentic patterns and architectures.
• Fluency with AI‑assisted and agentic development workflows.
• Strong sense of ownership and sound technical judgment.
• Comfort operating with ambiguity and turning it into shipped reliable product.
• A strong product mindset and customer orientation.

Preferred Qualifications

• Experience building agentic systems in fintech or other regulated industries.
• Experience as a founding engineer or early technical contributor in high‑growth environments.
• Demonstrated ability to ship technically complex systems in regulated contexts that customers actively rely on.
• Meaningful open‑source contributions, particularly in AI or developer tooling.

Employment eligibility to work with American Express in the UK is required as the company will not pursue visa sponsorship for these positions.

At American Express, our culture is built on a 175-year history of innovation, shared values and Leadership Behaviors, and an unwavering commitment to back our customers, communities, and colleagues. From delivering differentiated products to providing world‑class customer service, we operate with a strong risk mindset, ensuring we continue to uphold our brand promise of trust, security, and service.

We back you with benefits that support your holistic well‑being so you can be and deliver your best. This means caring for you and your loved ones' physical, financial, and mental health, as well as providing the flexibility you need to thrive personally and professionally:

• Competitive base salaries
• Bonus incentives
• Support for financial‑well‑being and retirement
• Comprehensive medical, dental, vision, life insurance, and disability benefits (depending on location)
• Flexible working model with hybrid, onsite or virtual arrangements depending on role and business need
• Generous paid parental leave policies (depending on your location)
• Free access to global on‑site wellness centers staffed with nurses and doctors (depending on location)
• Free and confidential counseling support through our Healthy Minds program
• Career development and training opportunities

Offer of employment with American Express is conditioned upon the successful completion of a background verification check, subject to applicable laws and regulations.