Backend Engineer – Python / FastAPI / LLM Pipelines | 100% Remote

🚀 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.