Job Title: Founding Full-Stack Software Engineer – AI for Biopharma Location: Barcelona, Spain Employment Type: Full-time Compensation & Benefits: From €70,000 Gym membership Hybrid model, but with regular onsite collaboration strongly preferred About the Company: Equator is a newly founded AI-native startup building next-generation software for the biopharma industry. Their mission is to solve one of the sector’s biggest challenges: knowledge management across scientific, commercial, and operational teams. Equator’s platform uses AI agents, knowledge graphs, and structured data systems to help biopharma organizations understand, compare, and act on their internal information. The result is a smarter, more proactive way for teams to collaborate and make decisions. This is an early-stage, senior, fast-moving environment where you’ll help shape the product, architecture, and engineering culture from the very beginning. Job Summary: As a Founding Full-Stack Engineer, you will build core product features end-to-end across backend and frontend. You will collaborate directly with the founders and play a key role in designing the technical foundation for an AI-native product serving complex biopharma workflows. Key Responsibilities: Architect scalable, auditable backend systems (Python, PostgreSQL, modern frameworks) Build APIs enabling seamless collaboration between humans and AI agents Develop clean, modular frontend interfaces using React, Next.js, and TypeScript Implement and maintain data-heavy systems and structured knowledge frameworks Write clean, precise code and contribute to strong engineering standards Collaborate closely with founders, designers, and early users to deliver impactful features Influence product, technical direction, and architectural decisions as a founding engineer Required Qualifications: 4–6 years of software engineering experience (mid to senior level) Strong backend engineering skills withPython Proficiency in React, Next.js, TypeScript, Node.js Experience building data-heavy or versioned backend systems Strong clean-code discipline and architectural thinking English (Advanced/C1+) Valid Spain work permit (no sponsorship available) Nice-to-Have Skills: Experience with AI agents or LLM-native applications Knowledge of Supabase, Postgres, RLS, versioning systems Familiarity with Radix, Tailwind, shadcn/ui, Inngest, Modal, Zod Engineering degree; PhD is a plus Background in life sciences, biopharma, or complex scientific domains What Equator Offers: Opportunity to join as one of the first engineers and shape the product from day one High-impact work solving real problems for biopharma teams A collaborative culture that values in-person interaction Hybrid model with strong preference for onsite work in the Barcelona office