Senior / Lead Security Engineer, Cloud Infrastructure

Position Overview

At Klaviyo, we value the unique backgrounds, experiences, and perspectives every team member brings, empowering creators to own their destiny. As a Lead Security Engineer on the Infrastructure Security Team, you will strengthen our security posture across Klaviyo’s technology environment by developing robust security architectures, implementing scalable security controls, and mentoring junior security engineers. You will leverage your expertise—whether in cloud security, identity and access management, data protection, secure systems design, or other areas—to evaluate and harden our infrastructure, collaborate with cross-functional teams, and drive innovative AI-powered security solutions.

Key Responsibilities

• Secure Klaviyo's infrastructure by designing, implementing, and maintaining scalable security controls across cloud, on-prem, and hybrid environments.
• Evaluate and improve security configurations and policies to reduce risk and enable secure-by-default architectures.
• Collaborate with engineering and IT teams to embed security practices and develop repeatable security patterns in the development and deployment lifecycle.
• Lead threat modeling, risk assessments, and architecture reviews in areas aligned with your specialty.
• Develop automated solutions and infrastructure-as-code to ensure consistent and reproducible security outcomes.
• Stay ahead of emerging threats and advocate for innovative security solutions aligned with business needs.
• Help define and champion security standards and best practices across the organization.

Required Qualifications

• Experience Required: 5+ years in infrastructure or security engineering roles with deep knowledge in one or more focus areas (e.g., cloud security, IAM, endpoint security, data protection, detection engineering, compliance)
• Comfortable navigating ambiguity and defining priorities in a broadly scoped role.
• Experienced working in modern cloud environments such as AWS, GCP, or Azure.
• Familiar with infrastructure-as-code tools such as Terraform, CloudFormation, or Pulumi.
• Proficient in secure systems design, threat modeling, and vulnerability management.
• Experience with AI agentic development and prompt engineering, including MCP (AWS Bedrock, OpenAI, Anthropic).
• Able to clearly articulate complex security topics to both technical and non-technical stakeholders.
• Passionate about security with a strong desire to learn from others and share expertise.

Preferred Qualifications

• Nice to have – certifications such as CISSP, CKS, or GCP/AWS Security certifications, or equivalent practical experience.

Benefits & Perks

• Generous benefits and a supportive work environment.