Lead Security Engineer, Enterprise Security (Denver)

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.As a Lead Security Engineer on the Enterprise Security team, you’ll play a central role in securing the corporate systems and platforms that Klaviyo runs on — spanning critical SaaS applications, identity and access, endpoints, Zero Trust network architecture, and perimeter security. You’ll partner across Engineering, IT, and the broader Security organization to mature existing programs, introduce new capabilities, and ensure our corporate security posture keeps pace with a fast-moving, AI-first company.This is a hands-on technical leadership role. You’ll be expected to deliver complex, cross-functional projects end to end, establish the design patterns and standards your team works from, and mentor the engineers around you. You bring deep expertise in at least one enterprise security domain and the range to work credibly across several others.At Klaviyo, AI fluency isn’t optional — it’s foundational. You’ll lead with AI at every stage of your work, from designing solutions to iterating on implementations, and you’ll take full ownership of the quality and security of what you ship.How You Will Make a DifferencePartner across several teams to drive the security architecture and lifecycle of Klaviyo’s critical SaaS applications, from procurement to offboardingEnsure the design and operations of identity and access management (IAM) across corporate SaaS platforms, including Just-in-Time Access (JITA), privilege management, and SSO/SCIM integrations; ensuring identity implementation meets or exceeds security standardsMature and expand Klaviyo’s Zero Trust network architecture — establishing web gateways, defining secure access policies, and building the foundation for a modern corporate network security postureChampion an AI-first approach to security engineering: designing, prototyping, and iterating with AI tools, and owning the responsible review and deployment of AI-generated artifactsManage and mature Cloudflare WAF policies and other perimeter security controls, ensuring coverage, tuning, and continuous improvementExpand and mature Klaviyo’s endpoint security strategy and tooling, partnering with IT, Detection, Response, and the broader security teams to achieve full endpoint visibility, proactive threat coverage, and rapid response capability across the fleetDeliver complex, multi-team projects by decomposing technical problems into actionable workstreams, setting the pace through all phases from requirements through productionWho You AreHave 7+ years of experience in security or infrastructure engineering roles, with demonstrated ownership of enterprise security domains such as SaaS security, IAM, Zero Trust, endpoint security, or cloud-delivered security servicesApproach every project AI-first: you design with AI, refine with AI, and take full responsibility for validating and owning what you deploy — you are not a passive consumer of AI outputHands-on by default — you are equally comfortable writing policy-as-code, reviewing architecture, and debugging a production issueProficient with Terraform for building and maintaining infrastructure-as-code across enterprise security systemsExperienced operating in AWS environments, with strong familiarity with cloud security services, IAM policies, and secure architecture patternsExperience with enterprise IdP solutions such as Okta, AWS CognitoExperienced with enterprise security tooling such as Cloudflare (WAF, gateway), Wiz (CNAPP/cloud security), and CrowdStrike (EDR/endpoint)Knowledgeable in secrets management, JITA, and modern identity patterns including SSO, SCIM, and privileged access workflows including SAML 2.0, SCIM, OAuth and OIDC — note this is not a dedicated IAM role; fluency in these areas supports broader enterprise security ownership, not identity program managementExperienced mentoring engineers and working through influence: you raise the bar for the people around you and hold team-wide technical standardsNice to have: experience with GCP or Azure environments, Spacelift for IaC orchestration, AI agent development, or securing AI coding platforms (e.g., Lovable, Vercel, Cursor)This role is hybrid, with an expectation of coming into the office three (3) times per week. 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:$175,200—$262,800 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 platforms, or unsolicited calls.By clicking Submit Application you consent to Klaviyo processing your Personal Data in accordance with our Job Applicant Privacy Notice. If you do not wish for Klaviyo to process your Personal Data, please do not submit an application.You can find our Job Applicant Privacy Notice here and here (FR).