Backend Engineer – Python / FastAPI / LLM Pipelines | 100% Remote We are looking for an experienced Backend Engineer to join an international technology project focused on building an intelligent platform that combines Python backend development, APIs, LLM-based agentic workflows and large-scale data processing .

Location: Spain Work model: 100% Remote Environment: International team ️ English: Good professional working proficiency required What will you be working on? You will help build and operate the Python backend behind an AI-powered platform used to process, compare, update and evaluate complex technical content.

Your responsibilities will include: Designing and maintaining REST APIs using Python and FastAPI . Developing typed API schemas with Pydantic and strong typing practices. Building asynchronous backend components and secure endpoints. Developing agentic AI pipelines using LangGraph and LangChain . Implementing workflows for content discovery, matching, editing, validation and evaluation.

Integrating Azure

OpenAI models using structured outputs and function/tool calling. Developing RAG-based solutions using embeddings and FAISS . Implementing grounding, provenance and hallucination-control mechanisms. Processing engineering datasets and large structured XML documents.

Performing data transformations using pandas and openpyxl . Developing database integrations using SQLAlchemy 2.x, PostgreSQL and AWS Aurora .



Containerizing and deploying backend workloads using Docker and AWS ECS/Fargate .

Working with AWS services such as ECR, Secrets Manager, RDS and SSO . Maintaining automated testing practices using pytest . What are we looking for? Strong professional experience with Python . Solid experience developing APIs with FastAPI .

Experience with Pydantic, async Python and typed backend development .

Experience with SQLAlchemy and PostgreSQL . Hands-on experience developing LLM applications using LangGraph and/or LangChain .

Experience integrating OpenAI or Azure OpenAI APIs . Knowledge of RAG, embeddings, vector search and structured LLM outputs .

Experience implementing techniques to reduce hallucinations and improve LLM output quality.

Experience processing structured or semi-structured datasets. Knowledge of Docker and AWS cloud services .

Experience with automated testing using pytest .

Experience with XML processing is highly valued.

Experience with AWS Aurora, ECS/Fargate or RDS Data API is a plus. Good professional English communication skills.

Technology Stack

Python · FastAPI · LangGraph · LangChain · Azure OpenAI · RAG · FAISS · Pydantic · SQLAlchemy · PostgreSQL · AWS Aurora · Docker · ECS/Fargate · pandas · XML · pytest If you enjoy working at the intersection of backend engineering, generative AI and cloud-based data processing , we would love to hear from you.

📌 Backend Engineer - Python / FastAPI / LLM Pipelines | 100% Remote (Vitoria-Gasteiz)
🏢 Infoser New Technologies
📍 Vitoria-Gasteiz