Sr. Staff Engineer, Applied AI (Customer Agent)

<div class="content-intro"><p><em>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 <a class="_ymio1r31 _ypr0glyw _zcxs1o36 _mizu194a _1ah3dkaa _ra3xnqa1 _128mdkaa _1cvmnqa1 _4davt94y _4bfu18uv _1hms8stv _ajmmnqa1 _vchhusvi _kqswh2mm _ect4ttxp _syaz13af _1a3b18uv _4fpr8stv _5goinqa1 _f8pj13af _9oik18uv _1bnxglyw _jf4cnqa1 _30l313af _1nrm18uv _c2waglyw _1iohnqa1 _9h8h12zz _10531ra0 _1ien1ra0 _n0fx1ra0 _1vhv17z1" href="http://klaviyo.com/careers" data-renderer-mark="true">klaviyo.com/careers</a> to see how we empower creators to own their own destiny.</em></p></div><h1>Senior Staff Engineer, Applied AI (Customer Agent)</h1> <h2><strong>About the Team:</strong></h2> <p>Our Engineering team builds the AI systems that power how brands run their businesses on Klaviyo. We move fast, ship in production, and hold a high bar for what "AI-native" actually means: systems that make real judgment calls, not demos.</p> <p>The Customer Agent team is one of the newest and most ambitious groups in that org, based in Boston and working in-office: we're building a conversational AI system that lets brands serve their own customers at a scale no human support team could match. We're still small enough that a single senior engineer can shape how the whole platform evolves. We're past the demo stage: the team ships changes against live customer traffic, measures quality with real evaluation frameworks, and treats reliability as a product feature, not an afterthought.</p> <h2><strong>About the Role:</strong></h2> <p>As Senior Staff Engineer, you'll set technical and product direction for Customer Agent end to end, building a 0-to-1 agentic product with the speed and ownership of a startup, backed by the scale and resources of one of the most innovative tech companies on the East Coast, while staying hands-on with the hardest problems yourself. This is a principal-caliber individual contributor role: we're looking for an engineer who has personally architected, built, scaled, and supported a production agentic system through everything that comes after the demo, and who acts as a force multiplier across the org through the strength of their technical judgment.</p> <h2><strong>How You'll Make an Impact:</strong></h2> <ul> <li>Set the technical and product direction for Customer Agent's core platform, from architecture through production.</li> <li>Take on the platform's hardest technical problems personally: orchestration, evaluation, guardrails, memory & context, self-healing/improving and failure handling for non-deterministic systems.</li> <li>Write and ship code, review designs, and make the calls other engineers can't make alone.</li> <li>Build architecture and frameworks that other engineers and teams adopt, and mentor through design reviews rather than direct management.</li> <li>Partner with product, design, data science, and go-to-market leaders to shape the roadmap, not just execute against it.</li> <li>Evaluate emerging AI technologies and bring the ones worth betting on into production.</li> </ul> <h2><strong>What We're Looking For:</strong></h2> <ul> <li>You've architected, built, scaled, and supported a production agentic system end to end, not just prototyped one: real orchestration, evals, guardrails, and non-deterministic failure handling. You've owned