Software Engineer Ii Infrastructure Security

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 Software Engineer on the Infrastructure Security team, you will build and operate the systems that help Klaviyo engineers ship secure software with confidence. You will:

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
Collaborate with senior engineers on system design and architecture, contributing ideas and technical solutions
Identify performance, reliability, and security issues in distributed systems and drive improvements
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
Partner with product-facing and platform engineers to ship impactful, secure solutions
Who you are
You have 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 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 communicate clearly, collaborate well, and enjoy working through technical problems as a team
You regularly use modern developer tooling, including AI-powered tools, to improve productivity and code quality
Nice to have
Experience building or integrating security-focused systems (e.g. secrets management, IAM, authn/z, policy enforcement)
Familiarity with service meshes, API gateways, or zero-trust architectures
Experience improving performance in distributed systems or debugging complex multi-service workflows
Tech Stack

Klaviyo’s platform is primarily built with Python and React and runs on AWS. Engineers join us from a wide range of technical backgrounds and are supported in learning our stack. Core technologies include:

Python / Django / FastAPI
MySQL / Redis / Memcached
RabbitMQ / Celery / Apache Kafka / Apache Pulsar
AWS / Terraform / Kubernetes
Location & Work Model

This role is based in Dublin, Ireland and follows a hybrid working model. Klaviyo supports work authorization and relocation for this position.

At Klaviyo, we enjoy tackling meaningful engineering challenges and value people who take ownership, learn continuously, and collaborate openly. We are committed to building inclusive teams and encourage applications from candidates of all backgrounds.

We use Covey as part of our hiring and / or promotional process. For jobs or candidates in NYC, certain features may qualify it as an AEDT. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications. We began using Covey Scout for Inbound on April 3, 2025.

Please see the independent bias audit report covering our use of Covey here

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