Sr. Lead Engineer - Customer Agent

Job Summary

Join us at Klaviyo and help build Customer Agent, a conversational AI system that enables brands to interact with their customers at a scale they have never achieved before. 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.

How You Will Make a Difference

• 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

• 12+ 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.
• Prominent ability to lead complex, multi-quarter technical initiatives involving multiple teams and stakeholders.
• Proven 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.

Qualifications

• Experience with large-scale systems, personalization, and real-world customer outcomes.

Pay & Benefits

The base salary offered for this position is determined by several factors, including the applicant’s job-related skills, relevant experience, education or training, and work location. In addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility.

Your recruiter can provide more details about the specific salary/OTE range for your preferred location during the hiring process.

This role may require up to 10% travel for purposes such as new hire onboarding, client or partner work if applicable, team meetings, and industry events. Travel is coordinated in advance.

About Klaviyo

We empower creators to own their destiny by making first-party data accessible and actionable like never before. We see limitless potential for the technology we’re developing to nurture personalized experiences in ecommerce and beyond. To reach our goals, we need our own crew of remarkable creators—ambitious and collaborative teammates who stay focused on our north star: delighting our customers.