Back End Developer

Pioneers; Madrid; Remote; EUR 55,000 - 85,000; Full time

Benefits offered by this job

Flexible PTO

Remote-first setup

Job summary

Pioneers in Madrid is seeking a backend engineer to own features end to end, from API design to event-driven pipelines that support recruiters.

You will build Python backend services, design serverless workflows with AWS, implement LLM-powered automation, and improve data models and queries across relational and NoSQL storage. Remote-friendly startup culture with daily overlap with New York.

Qualifications

• 3+ years of backend engineering experience with Python.
• Hands-on experience with AWS serverless services and event-driven architectures.
• Strong understanding of REST, queues and data modeling.
• Experience building or integrating LLM-powered automated workflows.
• Professional working proficiency in English
• The right to work in Spain (EU citizenship or a valid Spanish work permit)
• Comfort working remotely in a fast-moving team, with a daily afternoon overlap with New York

Responsibilities

• Build and maintain Python backend services and REST APIs.
• Design serverless workflows using AWS Lambda, API Gateway, SQS, Step Functions, DynamoDB, PostgreSQL and S3.
• Implement automated workflows and scoring systems powered by LLMs.
• Improve schemas, queries and data flows across relational and NoSQL storage.
• Contribute to CI/CD, observability and monitoring.
• Collaborate with product and frontend on API design and data contracts.
• Debug performance, race conditions and data integrity issues in asynchronous pipelines.

Skills

Python backend

Backend engineering

REST APIs

AWS serverless

LLM workflows

Data modeling

English proficiency

Spanish work permit

Tools

AWS Lambda

API Gateway

SQS

Step Functions

DynamoDB

PostgreSQL

S3

Python

Job description

We're a fast-growing startup building a recruitment platform. Our product helps recruiters spend less time on manual work, using LLMs to automate screening, scoring and the workflows around them.

What you'll do

You'll own features end to end - from API design and data models to the event-driven pipelines that support recruiters.

• Build and maintain Python backend services and REST APIs.
• Design serverless workflows using AWS Lambda, API Gateway, SQS, Step Functions, DynamoDB, PostgreSQL and S3.
• Implement automated workflows and scoring systems powered by LLMs.
• Improve schemas, queries and data flows across relational and NoSQL storage.
• Contribute to CI/CD, observability and monitoring.
• Collaborate with product and frontend on API design and data contracts.
• Debug performance, race conditions and data integrity issues in asynchronous pipelines.

What you'll bring

• 3+ years of backend engineering experience with Python.
• Hands-on experience with AWS serverless services and event-driven architectures.
• Strong understanding of REST, queues and data modeling.
• Experience building or integrating LLM-powered automated workflows.
• Professional working proficiency in English
• The right to work in Spain (EU citizenship or a valid Spanish work permit)
• Comfort working remotely in a fast-moving team, with a daily afternoon overlap with New York

What we offer

• Flexible PTO
• Remote-first setup with
• Real ownership: you'll ship features end to end