Staff Backend & AI Engineer, Madrid

Job summary

Responsibilities

As a Staff Backend & AI Engineer, you will be responsible for the design, development, deployment, and operation of business-critical AI features. Previous experience implementing AI features is a must.

• Collaborate on requirements analysis to design the right technical and business solutions for our customers.
• Propose innovative solutions by staying ahead of AI landscape trends and emerging technologies.
• Own key responsibilities in the design, architecture, and end-to-end delivery of AI-driven modules.
• Write clean, scalable, and maintainable code while ensuring proper testing, deployment, and monitoring.
• Continuously improve code quality through regular refactoring, debugging, and performance enhancements.

What they're looking for

• AI experience is a must for this position: Strong knowledge of LLMs and hands-on experience building with them - including usage, prompting and model integration.
• Familiarity with AI frameworks (e.g., LangChain, LlamaIndex, AutoGen) and modern AI architectures such as RAG, vector databases, reranking, and performance optimization.
• 5+ years of experience in back-end development using Python, TypeScript/Node.js, or Java, with a focus on security, scalability, availability, and performance.
• Full-stack development experience is a strong plus.
• Nice to have: Ideally you will have worked with AWS in a production environment and understand how to design for, deploy on and get the best out of, the environment and services…

Tech stack

• LangChain
• LlamaIndex
• RAG
• Python
• TypeScript
• Node.js
• Java
• AWS