Full Stack Engineer - Knowledge Base Team

santander; Tuineje; Hybrid; EUR 60,000 - 90,000; Full time

Benefits offered by this job

Hybrid work model

Open Academy access

Competitive rewards

Job summary

Santander is seeking a Full Stack Engineer for the Knowledge Base team to design and deliver secure, scalable applications and APIs that transform enterprise data into trusted knowledge for AI workflows.

Based in Madrid with a hybrid work model, you will collaborate with AI, Data, Cloud, DevOps, Product, and Security squads to ship production-grade capabilities at enterprise scale, focusing on reliability, security, and observability.

Qualifications

• 5+ years in full stack, backend, cloud, platform, or AI engineering.
• Experience building and operating production-grade distributed systems, APIs, or cloud applications.
• Hands-on experience with LLM applications, RAG, semantic search, or intelligent automation.
• Experience in a regulated enterprise environment.

Responsibilities

• Design and build full stack applications, backend services, APIs, and web interfaces for the Knowledge Base Platform.
• Develop data-to-knowledge workflows covering ingestion, chunking, embeddings, metadata, entities, relationships, retrieval, and validation.
• Build RAG and GraphRAG services combining vector search, graph traversal, reranking, grounding, and citations.
• Create secure integrations and tools for AI agents, including MCP-based interfaces.
• Deliver cloud-native solutions on AWS using containers, serverless, and event-driven patterns.
• Apply strong engineering practices across testing, security, observability, CI/CD, reliability, and cost.
• Collaborate across teams and contribute to technical design decisions and platform evolution.

Skills

Python

FastAPI

Django

React

TypeScript

JavaScript

HTML/CSS

AWS

Docker

Kubernetes

CI/CD

APIs

Distributed systems

LLM applications

RAG knowledge

Education

BSc or MSc in Computer Science, Software Engineering, or related field

Tools

Docker

Kubernetes

Infrastructure as Code

AWS Cloud

Job description

Full Stack Engineer - Knowledge Base Team

Country:

IT STARTS HERE

Santander ( www.santander.com ) 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.

Our mission is to contribute to helping 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.

THE DIFFERENCE YOU MAKE

CDAIO / AI TECH is looking for a Full Stack Engineer based in Madri d to join the Knowledge Base team .

You will build and operate secure, scalable applications, APIs, and user experiences that transform enterprise data into trusted knowledge for RAG, GraphRAG, semantic search, and AI agents .

Working with AI, Data, Cloud, DevOps, Product, and Security teams, you will deliver production-grade capabilities at enterprise scale.

Key responsibilities:

• Design and build full stack applications, backend services, APIs, and web interfaces for the Knowledge Base Platform.
• Develop data-to-knowledge workflows covering ingestion, chunking, embeddings, metadata, entities, relationships, retrieval, and validation.
• Build RAG and GraphRAG services combining vector search, graph traversal, reranking, grounding, and citations.
• Create secure integrations and tools for AI agents, including MCP-based interfaces.
• Deliver cloud-native solutions on AWS using containers, serverless, and event-driven patterns.
• Apply strong engineering practices across testing, security, observability, CI/CD, reliability, and cost.
• Collaborate across teams and contribute to technical design decisions and platform evolution.

WHAT YOU'LL BRING

Our people are our greatest strength. We value diverse perspectives and empower individuals to make an impact.

Professional Experience

• 5+ years in full stack, backend, cloud, platform, or AI engineering. (Required)
• Experience building and operating production-grade distributed systems, APIs, or cloud applications. (Required)
• Hands-on experience with LLM applications, RAG, semantic search, or intelligent automation. (Required)
• Experience in a regulated enterprise environment. (Preferred)

Education

• BSc or MSc in Computer Science, Software Engineering, or a related field, or equivalent practical experience. (Required)

Languages

• Spanish proficiency. (Required)
• High level of English. (Preferred)

Hard Skills

• Strong Python skills and experience with FastAPI, Django, or Flask. (Required)
• Experience with React, TypeScript, JavaScript, HTML, and CSS. (Required)
• Strong knowledge of APIs, microservices, distributed systems, security, testing, CI/CD, and observability. (Required)
• Hands-on AWS, Docker, Kubernetes and infrastructure-as-code experience. (Required)
• Knowledge of RAG, embeddings, vector search, reranking, grounding, and evaluation. (Required)
• Experience with relational, document, vector, graph, or search databases. (Required)
• Knowledge of knowledge graphs, GraphRAG, agent frameworks, Amazon Bedrock, or MCP. (Preferred)

Soft Skills

• Strong problem-solving, ownership, and end-to-end delivery skills.
• Clear communication and effective collaboration with technical and non-technical stakeholders.
• Pragmatic judgment balancing speed, quality, security, reliability, and cost.

WE VALUE YOUR IMPACT

Your contribution matters , and it's recognized. You can expect a fair, competitive reward package that reflects the impact you create and the value you deliver. But we know rewards go beyond numbers.

We're enable our teams to go beyond through global opportunities and broad career paths.

Flexibility that works. Enjoy a hybrid working models -some days remote, some days onsite with your team-along with flexible hours.

Learning for life . Access hundreds of courses on our platforms, including exclusive access to our global learning space: Santander Open Academy (www.santanderopenacademy.com)

Competitive rewards. Receive a highly competitive salary with performance-based bonuses, motivating you to ke