Hello
Do you want to help us redefine how AI powers the future of Business Management software, not as an add-on, but as a core part of how people work, decide and grow?
About The Team
Our Engineering team is the engine behind Factorial, crafting the technology that makes HR simple, fast, and reliable for thousands of companies. If you love solving hard problems and want to build something that truly matters, come build it with us.
We're a team of 200+ Product Engineers building a Business Management solution that actually works for the people using it. Our core stack is Ruby on Rails and React, but the interesting work right now is building agentic workflows, LLM-integrated features, and systems that behave probabilistically rather than deterministically.
The API & Integrations team addresses particular challenges at Factorial. We sit at the intersection between product and platform. We own the product surface while designing developer experiences for internal and external developers of integrations.
- Build tools for Factorial product teams to publish in our extensive public API.




- Build an integrations framework to achieve the best user experience and developer experience when using integrations. Several Factorial products are already using this framework, and we keep expanding it.
- Enable our developer partners to extend Factorial and live the best developer experience. With the acquisition of YepCode, we will boost how we build integrations, placing AI at the center of the process.

What You’ll Do
As a Product AI Engineer at Factorial, you’ll help define and build the next generation of our AI‑native product using modern AI development practices.
- Build product using Spec-Driven Development.
- Design and implement AI Skills.
- Develop and maintain evaluation frameworks (Evals).
- Apply Retrieval-Augmented Generation (RAG).
- Design human-in-the-loop and agentic workflows.
- Own systems end-to-end.
- Stay close to our customers.
- Collaborate closely with Prod

📌 AI Engineer (España)
🏢 Factorial
📍 España