About Us: Luzia is Europe's fastest-growing AI consumer company, redefining conversational AI with cutting-edge large language models and an unparalleled user experience. At Luzia, we ship fast: keep it simple, learn from every experiment, own outcomes, and build what our users need. it's how we win.
Hypergrowth startup with 80M+ users worldwide in under 3 years.
As a Backend Engineer, you'll join our engineering team in Madrid, driving the development of scalable, high-impact backend systems that power our AI‐driven products. The best candidates for this role often build side projects, contribute to open source, prototype backend architectures, or experiment with emerging AI capabilities.
Own backend services end to end - Build and maintain backend services in Python, owning features from design through deployment and monitoring.
Architect scalable backend systems - Design and maintain backend services and APIs that power real‐time AI interactions at scale. Ensure performance, reliability, and cost‐efficiency as we grow rapidly across markets.




Use modern AI‐assisted development tools to accelerate development cycles while maintaining strong engineering quality.
Raise the technical bar - Write clean, maintainable, well‐tested code. Think in systems, not just tickets - Anticipate bottlenecks before they happen - whether in performance, UX, cost, or scalability. 3 years of experience as a software engineer building and shipping production systems used by real users
Strong backend experience in Python, including designing and scaling APIs and services
Curiosity about working across the stack, including backend services and APIs that power mobile experiences
Interest in AI‐assisted software development, modern developer tooling, and experimenting with new ways of building products
This is a hybrid role based in our Madrid office - you'll combine working from our office and working from home

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