Full Stack Engineer

We're looking for a Full Stack Engineer for one of our clients who enjoys building new products from the ground up and is eager to help shape AI tooling for the mobility industry. Work across the full stack to solve complex problems using incomplete and messy data Design and evolve canonical data models Build pipelines to handle real-world data inputs Define and implement methods to resolve conflicting data Build and orchestrate agents that reason over data and take action Design agent behavior, including failure and recovery processes Create outputs that are explainable and auditable Ship features from idea through to production Help shape product direction, not just implement technical decisions Strong full-stack engineering skills (tech stack experience is flexible) Comfortable working with ambiguity and messy, inconsistent data Ability to take problems from concept to shipped solution Product-oriented mindset, focused on delivering outcomes Open to forming and revising strong opinions as the project evolves Demonstrated ability to think creatively and critically about what you build Ruby on Rails (API) React / Next.js Python (data and AI orchestration) Competitive salary: €40,000 to €80,000 Meaningful equity Flexible working (3 days in office) Barcelona HQ with beachfront location Generous holiday allowance plus public holidays Team off-sites in exciting locations