Frontier Agentic AI Engineer — AI Lab

IT STARTS HERE

Santander () is evolving from

Country:
Spain

Santander () is evolving from a global, high-impact brand into a technology-driven organization
, and our people are at the heart of this journey.
Together
, we are driving a customer-centric transformation that values bold thinking, innovation
, and the courage to challenge what’s possible. This is more than a strategic shift. It’s a chance for driven professionals to grow, learn, and make a real difference. Our mission is to contribute to help more people and businesses prosper. We embrace a strong risk culture and all our professionals at all levels are expected to take a proactive and responsible approach toward risk management.

Our Chief Data & Artificial Intelligence Officer (CDAIO) division is building a world-class AI & Data team to make a difference in the lives of over 170 million people worldwide, through one of the largest banks in the world.

We are undergoing one of the biggest transformations in our history and technology is at the heart of our strategy. Join our team to play a part in one of the most important technological projects for the financial sector in the world.

Santander AI Lab (CDAIO) is looking for an Frontier Agentic AI Engineer based out of Madrid, Spain
. The AI Lab is the applied innovation engine of one of the world’s largest banks. We detect emerging opportunities, build working prototypes, validate them with real data, and transfer them to scale. We work with Anthropic, Sakana AI, AWS, ICMAT, CMU, INRIA and other world-class partners. Our published research (arXiv:, arXiv:) sets the formal foundation for everything we build.

• Designing, building and deploying production-grade agentic AI systems — multi-agent orchestration with real memory, planning, tool use and error recovery. Not demos. Systems that work.
• Developing and fine-tuning small and medium language models (SLMs) for regulated banking use cases, including custom evaluation frameworks and domain-specific benchmarks.
• Architecting and implementing MCP servers, A2A protocols, and federated API layers that allow AI agents to operate across the group’s multi-country infrastructure.
• Prototyping new ideas in two-week sprints: hypothesis, architecture, code, functional demo, one-pager. This is the lab’s operating rhythm — you need to thrive in it.
• Collaborating with researchers, data scientists and business stakeholders to translate complex technical concepts into tangible bank value — Alchemy-style transformations of legacy assets.
• Keeping the lab at the frontier: monitoring emerging research, evaluating new tools (Harness Engineering, Kiro, Windsurf, Devin), and integrating them into the lab’s workflow when they add real value.
• Producing clean, tested, observable code that can be handed off to the AI Science team for production scaling. You own your code end-to-end.

Our people are our greatest strength. Every individual contributes unique perspectives that make us stronger as a team and as an organization. We’re enabling teams to go beyond by valuing who they are and empowering what they bring. The following requirements represent the knowledge, skills, and abilities essential for success in this role. Reasonable accommodations may be made to enable individuals with disabilities to perform the essential functions.

• 4–8 years of software engineering or AI engineering experience, with at least 2 years building and maintaining LLM-powered systems in production environments — not in notebooks. (Required)
• Demonstrated hands‑on experience designing and deploying multi‑agent AI systems with real‑world complexity: memory management, stateful orchestration, tool use, multi‑step planning, and graceful failure recovery. (Required)
• Experience fine‑tuning or adapting language models (SFT, LoRA, RLHF) for domain‑specific tasks, including dataset curation and evaluation design. (Required)
• Track record of delivering complete systems independently within tight timelines — from architecture decision to production‑ready code. Portfolio of real systems, not just demos. (Required)
• Experience…