Senior Software Engineer (Backend, Python)

About the role

Luzia, an AI consumer company with a strong presence in Latin America, is hiring a Backend Engineer in Madrid. You will join the engineering team and help build scalable, high-impact backend systems that power its AI-driven products, shaping how AI feels as a product.

Key responsibilities

• Design and implement fast, intuitive AI product experiences, working closely with product and design to prototype ideas and turn AI capabilities into simple experiences.
• Build and maintain backend services in Python, owning features from design through deployment and monitoring.
• Design and maintain backend services and APIs that power real-time AI interactions at scale, ensuring performance, reliability and cost-efficiency.
• Prototype quickly, validate with users and iterate based on feedback, using modern AI-assisted development tools.
• Work with AI engineers, product managers, designers and growth teams to turn experiments into production-ready systems.
• Write clean, well-tested code, contribute to architecture decisions and improve developer experience.
• Anticipate bottlenecks in performance, UX, cost and scalability, and proactively improve observability and reliability.
• Mentor colleagues through code reviews and help shape an engineering culture focused on ownership and craftsmanship.

Required profile

• More than 3 years of experience building and shipping production systems used by real users.
• Strong backend experience in Python, including designing and scaling APIs and services.
• Hands-on experience building AI agents end-to-end, including tool use, orchestration, evaluation and shipping to production.
• Experience building or integrating AI/LLM-powered features in consumer-facing products.
• Comfort in fast-paced startup environments with ambiguity and rapid iteration.
• Strong product intuition and ownership mindset.

Required skills

• Python
• Building and scaling APIs and services
• AI agent development (tool use, orchestration, evaluation)
• Nice to have: experience with LangGraph and/or LangChain

The role is hybrid, combining work from the Madrid office and from home. Applications are submitted through the company's application link.