Software Engineer II - Flows Platform

About this role

*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.*

### About the Role

Klaviyo is looking for a Software Engineer II to join the Flows Platform team. In this role, you will help build and operate the core engine that powers all automated lifecycle programs at Klaviyo. You’ll play a critical part in delivering robust, high-scale backend solutions that process billions of events, send millions of messages, and ensure our customers’ automations run reliably and without delay.

As a Software Engineer II, you’ll tackle complex challenges, explore multiple solutions, and weigh business and technical trade-offs to determine the best path forward. You’ll actively contribute to team discussions and help shape important technology decisions. You'll also be responsible for shipping well-designed, thoroughly tested solutions that prioritize reliability and performance.

On the Flows Platform team, we focus on the core of Klaviyo’s automation engine, ensuring that hundreds of millions of actions per day are processed accurately and efficiently to power user workflows. Our work revolves around the core backend systems that determine who receives a message and when, handling complex logic for triggering, filtering, and scheduling at massive scale. We also manage the data stores and infrastructure that support these operations, ensuring reliability while we actively re-architect our stack to support the next generation of event-driven features.

We are responsible for:

• Core Execution E...