Lead Software Engineer, Infrastructure Security

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.

Team Overview

The Infrastructure Security team makes it simple and easy for engineers to make secure choices while developing world-class software at high speed. Security is built in by default—seamless and effortless—making engineers’ lives better and Klaviyo more secure.

Our work sits at the intersection of security, infrastructure, and software engineering. We build cloud-native platforms and services that are reliable, secure, and performant at global scale, forming the foundation that Klaviyo engineers rely on every day.

This role is for engineers who enjoy building modern distributed systems, care about security and reliability, and want to have real impact across a large engineering organization.

How you’ll make an impact

As a Lead Software Engineer on the Infrastructure Security team, you will set the technical direction and lead security strategy for Klaviyo’s infrastructure. You will build and operate the systems that help Klaviyo engineers ship secure software with confidence. You will:

Set the technical vision and long-term strategy for security built into the SDLC and product infrastructure.

Lead, design, build, and maintain cloud-native security services used across Klaviyo

Own meaningful components and services end to end, from implementation through production operation

Improve the availability, scalability, latency, and efficiency of infrastructure security systems

Partner closely with product, platform, and security stakeholders on system design and architecture, contributing ideas and technical solutions

Identify performance, reliability, and security issues in distributed systems and drive improvements

Mentor senior and mid-level engineers, raising the bar for technical quality, security posture, and security culture across the organization.

Work extensively with technologies such as Python, Golang, AWS, Kubernetes, Terraform, and modern data stores

Participate actively in design reviews, code reviews, and whiteboarding sessions

Contribute to operational excellence through monitoring, alerting, and incident response

Participate in an on-call rotation with a focus on learning, prevention, and reducing operational toil

Build tooling, automation, and documentation that improve developer experience and security posture

Who you are

You have 8+ years of solid experience building and operating cloud-native, distributed systems in production

You are comfortable writing production-quality code in a language such as Python or Go

You have hands-on experience with AWS (or a similar cloud provider) and understand managed services, networking, and IAM concepts

You have experience working with containers and orchestration platforms such as Kubernetes

You have experience writing infrastructure as code such as Terraform

You are comfortable owning services and features independently, while knowing when to ask for feedback or support

You understand the fundamentals of scalable, multi-tenant architectures and secure system design

You care about reliability, performance, observability, and security—not just shipping features

You are comfortable participating in on-call and responding to production issues

You are an excellent communicator and collaborator. You lead technical discussions at the project and product-area level, write clear technical design documents and RFCs, and keep stakeholders aligned on progress, risks, and trade-offs.

Ability to handle yourself and complex syste