Senior Full Stack AI Engineer/LLM - Pharma Industry en Madrid, España

Can you imagine building AI-powered products that transform how business teams generate strategic insights?

Join our expert team to work on a Pharmaceutical sector product, contributing to the development of an AI platform that transforms enterprise knowledge into intelligent decision support.

You will apply your knowledge of LLMs , RAG , knowledge graphs and cloud-native technologies to build scalable AI solutions that enable business teams to make better evidence-based decisions through Synthetic AI Personas.

At ERNI, you are never just a number. Even if you work on an external project, you will feel part of the team and always supported.

How do we make this happen?

With people. Besides your team and manager, you will have several support figures like a godparent, who will help you with the practical and administrative aspects of daily life during your first 6 months.

And the second most important person after you, your mentor, who will guide you through your entire onboarding and career at ERNI. You will have regular 1:1 meetings with them, and recurrently, you will work on your development plan to define your short-, medium-, and long-term goals.

At ERNI, we highly value experience and technical knowledge. As a senior profile, you will have the space to continue growing, whether by deepening your technical skills or having greater influence on project decisions, with autonomy and the opportunity to share knowledge with other experts.

And if you are interested in mentoring, there is also space for that: supporting other ERNIans while still focusing on the technical excellence that sets us apart.

What you will bring

• Strong software engineering experience building production‑grade applications using Python as the primary language, with additional experience in TypeScript, https://jobeax.com/link/JSd7UYCSg572jJDY, FastAPI, Java or Rust .
• Hands‑on experience developing LLM‑powered applications using Azure OpenAI, OpenAI, Azure AI Services, Amazon Bedrock, Gemini or Anthropic , including multi‑provider LLM orchestration.
• Proven experience designing RAG and GraphRAG solutions, working with knowledge graphs, embeddings, vector search, semantic chunking, retrieval optimization and processing structured and unstructured enterprise data.
• Experience implementing agentic AI workflows using frameworks such as LangChain, LangFuse or Haystack , including prompt orchestration, tracing, evaluation and observability.
• Strong experience designing cloud‑native microservices and APIs, working with Snowflake , PostgreSQL , Docker , OpenShift , Kubernetes and modern CI/CD pipelines, while collaborating effectively with cross‑functional international teams.

You will be responsible for designing and developing AI‑powered capabilities based on LLMs, RAG and Synthetic AI Personas while building scalable backend services and enterprise integrations. You will collaborate closely with product owners, architects and engineering teams to transform business requirements into reliable AI solutions, continuously improving quality, performance and scalability.

What if the project ends?

We work on a wide variety of projects, technologies, and sectors, allowing you to keep growing in different environments. If a project ends or you feel ready for a new challenge, we will find another one that aligns with your professional development.

We ask you to be available for key meetings. Need to leave for a doctor’s appointment or to pick up your child from school? No problem. We trust you to deliver quality work within your 40‑hour workweek.

Our model is hybrid: we usually go to the office 2 days a week, though this depends on the project and team, but we love seeing each other’s faces; the best stories always happen in the office!

You will also enjoy:

And the salary?

We will discuss it during the first call. If it is important to you, feel free to ask!