Summary: Napptilus is seeking a proactive AI Engineer to design and build AI-powered applications, integrate LLMs, and collaborate with clients to rethink workflows with AI. Highlights: 1. Direct influence on product development and strategic direction 2. Hands-on and end-to-end AI system design and delivery 3. Opportunity to rethink work processes with AI for clients ABOUT NAPPTILUS Napptilus is a Barcelona\-based technology company with over 15 years building software, R\&D projects, and startups. Our AI team is the newest and fastest\-growing part of the company: a small group working with enterprise clients across Spain and internationally on LLM\-based systems that create real business impact. Your work here is visible and it matters. You'll have direct influence on what we build, how we build it, and where we go next. THE ROLE Our AI team works with clients in Spain and internationally to design and ship AI\-powered systems. The work is hands\-on and end\-to\-end: scoping problems with clients, designing architectures, and delivering production systems that hold up over time. We’re looking for engineers with a generalist profile who are genuinely curious about rethinking how work gets done with AI. Not just using the tools, but figuring out what becomes possible when you build around them, both internally and for clients. WHAT YOU’LL DO * Design and build AI\-powered applications, from early prototype through production * Integrate and orchestrate LLMs and agents into end\-to\-end products and workflows * Work directly with clients to understand their problems and explain your technical decisions * Help clients and the team rethink how they work with AI, contributing to a culture of experimentation and continuous improvement * Stay on top of the AI landscape and bring relevant ideas into the team WHAT WE’RE LOOKING FOR * 2\+ years of relevant engineering experience * AI tools are central to how you work, not optional: you use them daily (Claude Code, Codex, Cursor...) and you're always pushing to do more with them * Solid software engineering fundamentals * Hands\-on experience with LLMs, embeddings, vector stores, modern AI frameworks and APIs * Familiarity with at least one major cloud platform (AWS, Azure, or GCP) * Clear communicator who can explain technical decisions without jargon * Proactive and self\-directed: you move things forward without needing to be pushed * Fluent in English and Spanish. Comfortable understanding Catalan WHAT WE OFFER Salary Competitive, based on experience Vacation 25 days per year Health insurance Private, fully covered by the company Flexible benefits Meal vouchers (up to €220/mo) and transport (up to €136/mo) as pre\-tax salary Work model Hybrid, 2 days/week in office at Pier 01, Barcelona Tech City