Lead AI Engineer

At Klaviyo, we value the unique backgrounds, experiences and perspectives each Klaviyo (we call ourselves Klaviyos) brings to our workplace each and every day. We believe everyone deserves a fair shot at success and appreciate the experiences each person brings beyond the traditional job requirements. If you’re a close but not exact match with the description, we hope you’ll still consider applying. Want to learn more about life at Klaviyo? Visit klaviyo.com/careers to see how we empower creators to own their own destiny. Job Title: Lead AI Engineer – Marketing Service AI Location: Palo Alto, CA This role is based in our new Palo Alto hub. We operate a hub‑first model, with regular in‑office collaboration expected. About the Role At Klaviyo, we believe the future of software isn’t just better productivity tools for humans—it’s systems that can run, optimize, and adapt themselves based on outcome and reward signals. We’ve already built the infrastructure and applications that sit between businesses and consumers—serving 183,000+ customers, billions of consumer profiles, and hundreds of billions of messages and conversion events. Now we’re investing heavily in Marketing AI and Service AI: the shared services and agentic capabilities that power AI‑native experiences across Klaviyo. As a Lead AI Engineer in the AI Analytics organization, you’ll play a key role in designing and building scalable backend systems and user experiences that power our AI products and agentic solutions. You’ll own complex services end‑to‑end, contribute to architecture for high‑impact AI features, and partner closely with product managers, machine learning engineers, and data scientists to turn AI ideas into reliable, scalable production capabilities. This is a hands‑on, backend‑heavy role with opportunities to influence architecture, async processing pipelines, distributed systems, and more—without being the overall area tech lead. You’ll be based in our new Palo Alto office, a center of gravity for AI at Klaviyo—surrounded by teammates with deep ML and AI experience, and tightly connected to our other U.S. and international RD hubs. You’ll collaborate daily with engineers in Boston and other locations, and you’ll have a clear path to grow into broader technical leadership, staff/principal scope, or future people leadership if that’s the direction you want to go—without being constrained by hub location. How You’ll Make a Difference Design and build core AI services. Implement scalable, low‑latency backend systems and APIs that power our Marketing and Service AI capabilities for 183K+ customers, handling billions of events and interactions. Scale AI data and inference pipelines. Develop robust, reliable, and scalable data collection and processing pipelines so our generative and agentic models have the features, context, and feedback they need to perform well in production. Build and harden AI serving systems. Implement services that host and orchestrate AI models (LLMs, tools, evaluators, retrieval systems), with strong contracts, logging, and observability so other teams can depend on them. Evolve our agentic architecture. Help evolve how our agents plan, call tools, and react to feedback—shipping improvements that increase autonomy, reliability, and safety for both customer‑facing and internal workflows. Apply and refine best practices for AI systems. Use and help improve standards for evaluation, safety/guardrails, prompt and model management, offline/online tests, and incident response for AI‑backed systems. Collaborate across teams. Work closely with product, ML, data, and platform teams to clarify requirements, align on interfaces, and unblock dependencies for the services you own—especially across hubs and time zones. Mentor and uplevel teammates. Provide thoughtful code reviews, share patterns and examples, and help mid-level and junior engineers grow stronger in building distributed and AI‑powered systems. Help sha ... (truncated, view full listing at source)