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 (Madrid)
🏢 Infoser New Technologies
📍 Madrid