Sr. Staff Engineer - Customer Agent

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. Senior Staff Engineer - Customer Agent Are you looking for one of the most impactful AI-native leadership roles in Boston? Join us at Klaviyo and lead the team building Customer Agent, a conversational AI system that enables brands to interact with their customers at a scale they have never achieved before. Customer Agent is central to Klaviyo’s vision for AI-powered customer engagement. It delivers real-time, contextually aware conversations that help brands support, convert, and retain millions of consumers. We are just beginning to unlock what is possible, and we are looking for an engineering leader who is eager to define that future. 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. About the Role: We are seeking an experienced Senior Staff Engineer with deep expertise building and scaling agentic systems and AI-enabled products. You will shape how Customer Agent evolves into a highly extensible, reliable, and intelligent platform. You will drive technical strategy, lead architectural direction, and partner closely with product, design, data science, and engineering leaders to deliver industry-defining AI experiences. This role is ideal for a hands‑on technical leader who thrives in ambiguity, enjoys building from first principles, and wants to influence both product direction and engineering strategy. You will be expected to operate as a force multiplier across teams, leading through technical excellence, execution, and mentorship rather than direct people management. You will work on some of Klaviyo’s most important AI investments, helping define the next generation of conversational experiences while operating at the intersection of large-scale systems, agentic workflows, personalization, and real-world customer outcomes. How You Will Make an Impact: Lead the architecture, design, and implementation of Customer Agent’s core platform and AI capabilities. Drive technical strategy and long‑term system evolution for conversational AI experiences serving millions of users. Build and ship complex AI‑powered product features, balancing speed, quality, reliability, and customer impact. Partner closely with Product, Design, Data Science, GTM, and Engineering leaders to define product direction and execution plans. Make critical technical decisions around agent architectures, orchestration frameworks, retrieval systems, memory, tool use, evaluation, and reliability. Establish engineering best practices around observability, testing, monitoring, experimentation, and operational excellence for AI systems. Lead large, cross‑functional initiatives spanning multiple teams and organizations. Mentor engineers through technical leadership, design reviews, architecture discussions, and hands‑on collaboration. Evaluate emerging AI technologies and frameworks, identifying opportunities to create meaningful customer value. Influence engineering standards and contribute to the broader technical direction of Klaviyo’s AI platform. Who You Are: 10+ years of software engineering experience building and operating production systems at scale. Significant experience designing and shipping customer‑facing AI‑powered products or agentic systems. Strong backend engineering and distributed systems fundamentals, with the ability to reason about scale, latency, reliability, and operational tradeoffs. Demonstrated expertise with modern AI architectures, including LLM‑powered applications, retrieval systems, agent workflows, orchestration, evaluation frameworks, and guardrails. Proven ability to lead complex, multi‑quarter technical initiatives involving multiple teams and stakeholders. Strong product instincts and the ability to connect technical decisions to customer and business outcomes. Comfortable operating in ambiguous, fast‑moving environments and defining direction when requirements are incomplete. Excellent communication and collaboration skills across engineering, product, design, and executive audiences. Hands‑on builder who enjoys working directly in code and tackling difficult technical problems. Track record of influencing engineering organizations through technical leadership, mentorship, and execution excellence. Bonus Points Experience building conversational AI, customer support automation, or agentic workflow platforms. Experience with production evaluation systems, AI observability, human‑in‑the‑loop workflows, and reliability engineering for LLM‑powered products. Experience building 0→1 products or working in startup environments. Boston, MA – In-Office Role Massachusetts Applicants: It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability. Our salary range reflects #J-18808-Ljbffr Triwill Group