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?
Join us as a Founding Engineer in a brand-new Factorial spinoff
It's ambitious, and that's the point.
But this isn't an internal project. It's a spinoff with its own identity, its own pace, and its own team.
That said, strong Ruby on Rails experience on the backend and solid React or TypeScript on the frontend will go a long way.
If you've ever wanted to work in a small, scrappy team with the energy of an early‐stage startup but without the typical early‐stage uncertainty, this is that opportunity.
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 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 what we're building on top of that: agentic workflows, LLM‐integrated features,



systems that behave probabilistically rather than deterministically.
You have an entrepreneurial mindset and genuinely enjoy the early stage of building something from scratch.
~ You're comfortable working with Ruby on Rails & React and understand how to integrate AI models into scalable, cloud‐native environments.
~ You help teammates who are transitioning from deterministic to probabilistic thinking, not by lecturing, but by working through it together.
~4+ years in software engineering, with some track record (or serious curiosity) around shipping AI features.
~ You can explain a complex technical decision in English to someone who doesn't write code clearly, without condescension.

You will review code daily and get feedback on your own code at every pull request, from all team members, including juniors.
You will learn from the entire team, both on technical topics (performance, architecture...) and core skills, in an environm

📌 Software Engineer, Frontend (Barcelona)
🏢 Factorial Hr
📍 Barcelona