We're looking for a Senior Backend Engineer to help build the core systems that power how Lemonade prices insurance for millions of customers. You'll join our Pricing Team in Amsterdam, working on everything from our homegrown domain-specific language to AI-powered research pipelines that push the boundaries of actuarial science. Team Context Our Pricing Team operates at the intersection of complex mathematics and high-performance engineering. We've built our own DSL in TypeScript for actuarial calculations, compiled to Rust for production performance, and increasingly leverage AI to discover new pricing patterns. You'll work alongside actuaries who understand the logic of risk, but you'll be the one designing the technical architecture that makes their insights scale. We believe three things matter for every role at Lemonade: drive to push through challenges, efficiency that keeps standards high while moving fast, and adaptability that lets you pivot with data and AI insights. These aren't buzzwords, they're how we actually work. Our AI-first approach isn't just a tagline either. We're building the future of insurance with AI at the center, and we need people who are genuinely excited to learn and grow alongside these tools. IN THIS ROLE YOU'LL * Design and build core rating services that calculate prices for insurance products used by millions * Architect complex systems spanning TypeScript, Rust, and Python across different problem domains * Build AI-powered research pipelines that help actuaries discover new pricing insights * Create SDKs and code patterns that other teams can build on top of * Optimize performance-critical systems where milliseconds matter for customer experience * Collaborate with actuaries to translate complex mathematical models into scalable code * Lead technical decisions about system architecture, interfaces, and design patterns What you'll need * Adaptability, drive, and an efficiency mindset — we believe these matter most in human-AI collaboration * Deep experience with system design and architectural decision-making, not just API development * Strong proficiency in one of backend languages with ability to quickly pick up new ones (our stack includes TypeScript, Rust, and Python) * Experience building performance-optimized systems where technical choices directly impact business outcomes * Track record of designing complex technical systems from scratch, including interfaces and abstractions * Comfort working with heavy Kubernetes deployments and cloud-native architectures would be nice to have * Educational degree in Computer Science, Engineering, or equivalent experience * Ready to work in an office environment most days of the week * Enthusiasm about learning and adapting to the exciting world of AI — a commitment to exploring this field is a fundamental part of our culture