Founding Engineer

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Founding Engineer based in Spain. This is an opportunity to become the first engineering hire at an early-stage AI infrastructure startup with a working product and live revenue. You will work directly with the founder to shape the architecture, technical direction, and engineering culture from the ground up. The role centers on transforming a proven agentic system into production-grade infrastructure capable of serving up to a million users. You will have broad ownership across backend, infrastructure, frontend, and AI agent systems. With no engineering organization above you, your decisions will directly influence the product and future technical team. As the company grows, the role is expected to evolve toward a CTO-level position.