? 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 (España)
🏢 Infoser New Technologies
📍 España