Lead Software Engineer, Platform Engineering

Team Overview

The mission of the Platform Engineering team is to provide the infrastructure primitives, platforms, tooling, and guidance that let every engineering team at Klaviyo build, ship, and operate with confidence. We own the paved path for how product teams manage their services, applications, and data — spanning core infrastructure, observability, databases, and queuing.

As a Lead Software Engineer on the Platform Engineering team, you will set technical direction for our core platform services, ensuring our platform primitives scale with Klaviyo’s growth while remaining simple, reliable, and cost-efficient for the teams that depend on them. Your work will be highly visible and will directly shape how thousands of Klaviyo engineers build and ship products every day.

How you’ll make an impact

As a Lead Software Engineer, you will provide technical leadership across the Platform Engineering org while remaining hands-on with the systems you build. You will:

Build a deep understanding of engineering needs across the organization, guiding the design and development of the right platform primitives (infrastructure, databases, queuing, and more) and balancing the platform's vision with the practical needs of product teams

Set the technical vision and long-term roadmap for core platform services, translating organizational priorities into a clear, multi-year plan

Own the design, development, and evolution of foundational platform primitives that product teams rely on to ship quickly and safely

Lead cross-team initiatives that improve the availability, scalability, latency, and cost-efficiency of Klaviyo’s core platforms, and drive adoption of the resulting paved paths

Identify systemic gaps and architectural bottlenecks, and lead the design and delivery of solutions

Leverage technologies such as Python, Go, AWS, and Kubernetes to advance the platform, partnering closely with security, and product engineering leaders

Champion best practices across the organization, including technical design review, configuration as code, and defensive programming

Drive cost-optimization efforts across the platform — right-sizing infrastructure, improving resource utilization, and building the tooling and guardrails that make cost-efficiency the default

Mentor senior and mid-level engineers, raising the bar for technical quality and engineering craft across the Platform Engineering org

Participate in and help evolve on-call practices, with a focus on solving issues at the root, preventing recurrence, and minimizing alert fatigue

You’ve already experimented with AI in work or personal projects, and you’re excited to dive in and learn fast. You’re hungry to responsibly explore new AI tools and workflows, finding ways to make your work smarter and more efficient.

Who you are

BA or BS degree in Computer Science, related field, or equivalent experience

10+ years of experience designing, building, and operating large-scale distributed systems, with a track record of technical leadership

Deep, hands-on experience developing production software in Python and/or Go

Extensive experience working in cloud-native environments, with hands-on ownership of infrastructure as code (e.g. Terraform) and containerized platforms (e.g. Kubernetes)

Fundamental understanding of Linux and all layers of the networking stack; comfortable administering and debugging production systems

Experience across a range of platform-related domains such as API gateways & traffic management, observability, asynchronous processing, or database/storage platforms

Proven ability to independently own the full lifecycle of complex, cross-team platform initiatives — from discovery and technical design through rollout and long-term maintenance

Strong track record of mentoring engineers and influencing technical direction beyond your immediate team

Excellent communicator who writes clear technical design docs and RFCs, and keeps stakeholders aligned on progress, risk, and trade-offs

Comfortable handling complex systems in outage situations and driving failures to root cause and resolution

Nice to have

Familiarity with high-volume data processing and storage systems, including OLTP and OLAP databases

Experience with large-scale data ecosystems — e.g., ClickHouse, DynamoDB, MySQL, Kafka, Spark, Flink, Iceberg, or Airflow

Background in internal tooling or paved-path platform design

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 / Go

MySQL / Redis / Memcached

RabbitMQ / Celery / Apache Kafka / Apache Pulsar

AWS / Terraform / Kubernetes

Location & Work Model

This role is based in Boston, Massachusetts. 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.

Klaviyo is growing fast and we have openings for all skill levels across all of our teams. Learn more about our engineering culture at klaviyo.tech.

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:

$176,000—$264,000 USD