Senior Backend Engineer, GenAI

Job description

## **What you're applying for** Anyone can ship an AI agent. Shipping one that’s right ~98% of the time, with no human checking its work, takes different engineering. That’s what this team builds. We're looking for a Senior Backend Engineer to help push our AI customer-service agents closer to fully autonomous insurance service. You'd be joining the team behind the agent that talks to real customers every day over email, phone, chat, and SMS - handling policy questions, claims conversations, and verified documents end-to-end, with no human in the loop. This isn't a demo or a copilot. Real customers, real money, real stakes, every day. 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, build, and own production LLM agent systems end-to-end - deciding how the agent thinks, what it's allowed to do, and how it fails safely - Work on our real-time voice agent, where the hard problems are conversational: interruptions, mid-sentence tool calls, and keeping response times imperceptibly fast - Shape the next generation of our knowledge base - how the agent's knowledge is structured, curated, and served, so answers stay grounded as coverage grows - Ship changes as controlled experiments, measure them against thousands of replayed real conversations on our in-house eval platform, and graduate winners into production - Track cost per conversation across millions of LLM calls and find the wins that cut spend without cutting quality - Own what the model knows and says - the customer context it sees, the limits on what it may reveal, and the guardrails against confident nonsense - Build and operate scalable backend services in TypeScript/Node on Kubernetes/AWS with deep observability - if you ship it, you own it ## What you'll need - 6+ years building production-grade backend systems that real users depend on - Hands-on experience shipping LLM-powered features to production, including honest reckoning with non-determinism, hallucination, and cost - An evaluation mindset - you don't call a change "better" without a measurement, and you're comfortable with the statistics that back that claim - A track record of debugging distributed systems in production, and the discipline to find root cause across service boundaries - Fluency with agentic coding tools like Claude Code or Cursor, including the habit of treating AI-generated code with a senior reviewer's skepticism - The ability to pull your own numbers, design your own experiments, and measure your own impact - Ready to work in an office environment most days of the week