Requirements

8+ years of engineering experience with strong backend and distributed systems design skills
Proficient in Python and/or Go, and able to pick up the other quickly
Experienced with large-scale system architecture — familiar with the tradeoffs involved and able to apply them against real business constraints
Comfortable contributing to architecture and code directly; this is a hands-on role
Skilled in scaling infrastructure on AWS
Strong product and business mindset — you think beyond the code to understand customer impact
Self-directed and delivery-focused — you ship incremental value and iterate
Clear communicator who thrives in a high-autonomy, cross-functional environment
You've already experimented with AI in your work or personal projects and are excited to keep pushing on that

What you'll be doing

Own and drive the architecture of key components in Klaviyo's messaging pipeline — from ingestion and routing through to delivery and status tracking
Lead a team of engineers building and scaling highly-available, high-throughput services across one or more messaging channels
Design and implement scalable backend services in Python and/or Go
Work on a campaign pipeline that processes and delivers hundreds of millions of messages daily, growing to billions-scale
Bring clarity to ambiguous technical problems — breaking undefined challenges into concrete, actionable plans
Collaborate across product, deliverability, compliance, and platform teams to expand messaging capabilities
Drive best practices in system design, code quality, and engineering process across your team
Mentor and grow engineers, contributing to a high bar across the broader Messaging Infra organization
Build smarter systems and workflows by putting AI at the center of how you and your team work

This role may require up to 10% travel for purposes such as new hire onboarding, client or partner work if applicable, team meetings, and industry events. Travel is coordinated in advance.