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Klaviyo is seeking a Senior Lead Engineer to set technical and product direction for its Customer Agent platform—a conversational AI system enabling brands to serve customers at scale. This is a principal-caliber individual contributor role, not a management position, where you'll architect, build, and operate a production agentic system end-to-end.
You'll own the platform's hardest technical challenges: orchestration, evaluation frameworks, guardrails, memory and context management, self-healing mechanisms, and failure handling for non-deterministic systems. You'll write and ship code, review designs, and make architectural decisions that other engineers adopt. The role balances hands-on technical work with mentorship through design reviews and cross-functional collaboration with product, design, data science, and go-to-market teams.
Key responsibilities include setting the technical roadmap, taking on the platform's most complex problems personally, building reusable frameworks and architecture that other teams adopt, evaluating emerging AI technologies for production use, and partnering with leadership to shape product direction.
You must have architected, built, scaled, and supported a production agentic system end-to-end—not just prototyped one. You've learned production lessons: securing agents against misuse, handling non-deterministic failures, and maintaining reliability at scale. You've set technical direction for an entire product area before, stayed hands-on through code review and debugging, and your frameworks have been reused across multiple teams. You communicate complex technical trade-offs clearly to engineering, product, and executive audiences.
Nice-to-haves include experience running multi-tenant agent platforms at production scale, building 0-to-1 products or working in startups, and a track record with production evaluation systems, AI observability, or human-in-the-loop LLM workflows.
Based in Boston, MA. In-office role.
