Full Stack Software Engineer - People Systems

Lead People Technology EngineerKlaviyo is building an AI-first company—and that starts with how we support and scale our people.We're looking for a Lead People Technology Engineer to be the first dedicated AI engineer within our People Technology (KPPL) team. As an early leader in this space, you'll reimagine how our People teams operate in an AI-first world by shaping our architecture, standards, and long-term vision.You'll partner across People Operations, Talent Acquisition, Talent, and Finance to design and build intelligent systems that transform how we hire, develop, retain, and support Klaviyos globally. This role is not just about applying AI it's about defining how AI becomes embedded into the employee lifecycle at Klaviyo.AI-First People Systems & ArchitectureReimagine core People workflows (recruiting, onboarding, performance, daily tasks) through an AI-first lens, not just incremental automationDesign and build AI-powered workflows, copilots, and agents that automate and augment People processes across the employee lifecycleArchitect and implement systems that integrate across SaaS such as Workday, Greenhouse, Sana, and internal Klaviyo platformsPartner with our internal IT AI team and establish best practices for:Prompt engineering and evaluationLLM system design and orchestrationVersioning, testing, security, and observability of AI systemsEnable AI Use Cases (copilots, assistants, automated workflows) that drive faster execution and better decision-making for People teamsCollaborate with stakeholders to translate business problems into scalable AI solutionsDriving an AI-First Operating ModelIdentify high-leverage opportunities to replace manual workflows with AI-native solutionsDefine and track success metrics tied to efficiency gains, time savings, and operational effectivenessHelp the People organization shift toward AI-augmented ways of workingAct as a thought partner to People leadership on what's possible with AI, not just what's requestedResponsible AI, Privacy & Governance: Design systems that handle sensitive employee data with security, privacy, and trust at the corePartner with Security, Legal, and Global IT to ensure compliant and ethical AI deploymentCross-Functional Collaboration & EnablementWork closely with Security, IT, and GTM Systems to align on shared AI infrastructure and standardsContribute to and adopt company-wide AI patterns, tooling, and best practicesEnable People teams to leverage AI by building:Reusable frameworks and workflowsPlaybooks and training materialsHelp non-technical stakeholders confidently use and iterate on AI-powered toolsTechnical LeadershipAdvocate for scalable, well-governed AI systems that integrate cleanly into Klaviyo's broader tech ecosystemAct as a key voice in shaping how Klaviyo becomes AI-first internally, starting with People systemsWhat Makes You a Great FitPassion and Curiosity to experiment and reimagine People workflows5+ years of engineering or data engineering experience, with 2+ years building AI/ML or LLM-powered delivering tangible business outcomesProven ability to set technical direction and build 0?1 systems with meaningful organizational impactStrong experience with but not limited to:Python, SQL, and modern APIsLLM platforms (OpenAI, Claude, Gemini, etc.)LangChain and LangGraphDesigning AI-powered workflows, agents, or copilotsExperience integrating with enterprise SaaS systems (HRIS, ATS, etc.)Experience designing scalable systems, automation frameworks, and internal toolsExperience working with sensitive data and implementing responsible AI practicesStrong ability to translate ambiguous business problems into scalable technical solutionsBonus PointsExperience with People/HR systems (Workday, Greenhouse, Sana)Familiarity with workflow automation platforms (e.g., n8n, Workato, Zapier)Experience in high-growth SaaS environmentsContributions to AI governance, internal AI platforms, or experimentation frameworksWhy This Role Matters at KlaviyoThis is a foundational role in defining how Klaviyo becomes an AI-first company from the inside out.You won't just be implementing AI you'll be:Shaping how People teams operate with AIDefining standards for responsible, scalable internal AI systemsBuilding the blueprint for how AI is embedded across the businessIf you're excited about building from scratch, influencing across functions, and applying AI to core business workflows, this role offers a unique opportunity to have outsized impact.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 the cost of labor across various U.S. geographic markets. The range displayed below reflects the minimum and maximum target salaries for the position across all our US locations. 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.Base Pay Range For US Locations: $140,000 —$210,000 USDThis 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.Get to Know KlaviyoWe're Klaviyo (pronounced clay-vee-oh). 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. If you're ready to do the best work of your career, where you'll be welcomed as your whole self from day one and supported with generous benefits, we hope you'll join us.AI fluency at Klaviyo includes responsible use of AI (including privacy, security, bias awareness, and human-in-the-loop). We provide accommodations as needed.By participating in Klaviyo's interview process, you acknowledge that you have read, understood, and will adhere to our Guidelines for using AI in the Klaviyo interview Process. For more information about how we process your personal data, see our Job Applicant Privacy Notice.Klaviyo is committed to a policy of equal opportunity and non-discrimination. We do not discriminate on the basis of race, ethnicity, citizenship, national origin, color, religion or religious creed, age, sex (including pregnancy), gender identity, sexual orientation, physical or mental disability, veteran or active military status, marital status, criminal record, genetics, retaliation, sexual harassment or any other characteristic protected by applicable law.IMPORTANT NOTICE: Our company takes the security and privacy of job applicants very seriously. We will never ask for payment, bank details, or personal financial information as part of the application process. All our legitimate job postings can be found on our official career site. Please be cautious of job offers that come from non-company email addresses (@klaviyo.com), instant messaging