Senior Software Engineer, Platform Engineering

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.

The mission of the Platform Engineering team is to provide infrastructure primitives, platforms, tooling, and guidance to Klaviyo engineering.This role will specifically focus on our core platform services and developer experience, with an emphasis on making Klaviyo's platforms more cost-efficient at scale.

As a Senior Platform Engineer, you'll work on crafting a paved path for product teams to manage their services and applications. You will own the design and development of foundational platform services that enable Klaviyo's engineering teams to move faster with confidence while driving down the cost of running our infrastructure.

How you will make a difference

Ship foundational services to enable Klaviyo engineering to move faster with confidence.

Build a deep understanding of engineering needs across the organization, guiding the design and development of appropriate platform primitives (Infra, Databases, Queuing, etc), that align with the platform's vision and practically empower product teams.

Design, develop, and deliver software to dramatically improve the availability, scalability, latency, and cost efficiency of Klaviyo's core platforms, helping teams to better serve customers, operate within budget, and meet their SLOs.

Design and develop systems and processes that enable highly available and scalable applications.

Leverage technology such as Python, Go, AWS, and Kubernetes to advance Klaviyo's platform.

Mentor and pair with other Klaviyo engineers to build better software by focusing on performance, self-healing systems, configuration as code, and defensive programming.

Identify and drive cost-optimization opportunities across the platform — right-sizing infrastructure, improving resource utilization, and building tooling and guardrails that make cost efficiency the default for product teams

Who You Are

BA or BS Degree in Computer Science, related field, or equivalent experience.

5+ years of responsibility operating and scaling complex distributed systems.

Experience working in a cloud-native environment.

Proven experience developing applications in Python and Go.

Fundamental understanding of Linux and all layers of the networking stack.

Experience in a subset of platform-related areas such as Kubernetes, infrastructure as code, API gateways & traffic management, observability, or asynchronous processing tooling.

Exposure to or interest in measuring and optimizing infrastructure cost and utilization

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

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

Our salary range reflects the cost of labour in the country where the job post is advertised. 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 in Local Currency

€92.000—€138.0