We’re starting something new at Factorial: Chats. It’s a fresh area of the product, built around communication and, from day one, built with AI and agents doing real work in it, not just a chatbot bolted onto the side. No backlog gathering dust, no "how we’ve always done it." Just the problem, and whoever shows up to solve it.
We’re hiring a Senior or Staff engineer to help get Chats off the ground. Fullstack is idóneo, but if your expertise lies merely in mobile it works for us too
This isn’t just a new product, it’s a chance to rethink how software gets built. We’re creating an AI‑native product from scratch, where AI isn’t another feature but part of the core architecture and user experience. 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.
Fullstack experience (Rails/React/React Native), or deep React Native expertise if you’re mobile‑focused.
Solid experience as a software engineer, comfortable owning ambiguous problems end to end.
Communication: Comfortable working in English in a multicultural team.
Build Chats from zero: from the first architecture decisions to features real customers use every day.
Design and ship experiences with AI and agents at the core, not as an add‑on, this is central to what Chats is.
Ruby on Rails on the backend, React on web, React Native on mobile or focus on mobile if that’s your strength.
Adapt fast: priorities, scope and direction will shift as we learn. Partner closely with product and design to define what Chats becomes, informed directly by customer feedback.
Help shape the team itself: its practices, its bar for quality, an

📌 Senior/Staff Software Engineer (Barcelona)
🏢 Factorial Hr
📍 Barcelona