Staff AI Engineer — API & Integrations Architect

Factorial; Madrid; Hybrid; EUR 42,000 - 65,000; Full time

Benefits offered by this job

High growth environment

Private health insurance

Wellhub gym membership

Cobee benefits

Language classes

Office breakfast and fresh fruit

Food discounts with Nora

Pet-friendly office

Job summary

Factorial, Madrid-based HR platform, is seeking engineers to own the API and integrations framework end-to-end, from problem definition through shipping, monitoring, and iteration in production.

We value production-grade code, customer-focused thinking, and a track record of shipping real products. The team uses Ruby on Rails and React, with openness to other stacks and a strong emphasis on evolving internal frameworks and AI integration.

Qualifications

• :mature development practice and production-grade code ownership
• :

Responsibilities

• Own API and integrations surface end-to-end from problem definition to production
• Collaborate with Product and Design to shape API and integrations
• Maintain cross-product consistency across ATS, payroll, ERPs and more
• Stay close to customers through calls and feedback sessions
• Share knowledge and contribute to engineering best practices
• Help define AI roadmap elements like AI skills, evals, RAG and agentic workflows

Skills

Ruby on Rails

React

API design

Systems thinking

Product mindset

Tools

Public APIs

Job description

Factorial, Madrid-based HR platform, is seeking engineers to own the API and integrations framework end-to-end, from problem definition through shipping, monitoring, and iteration in production.

We value production-grade code, customer-focused thinking, and a track record of shipping real products. The team uses Ruby on Rails and React, with openness to other stacks and a strong emphasis on evolving internal frameworks and AI integration.