Lead Software Engineer - Email Platforms

Why You Should Join the Email Platforms Team:

The Email Platforms team at Klaviyo is building the next generation of infrastructure to support reliable, scalable, and performant email delivery. Our mission is to help Klaviyo reach enterprise scale by evolving and owning our email sending pipeline end-to-end. We're investing heavily in our homegrown email delivery infrastructure, giving us greater control, performance, and reliability in how we deliver emails for some of the largest brands in the world.

As a Lead Software Engineer on this team, you'll lead a group of engineers focused on designing and scaling high-throughput email delivery systems. You'll drive the architecture of our messaging infrastructure, own critical components of the email pipeline, and help shape the technical direction of the team. This is a hands-on role where you'll contribute to code, design, and lead strategy. Your work will directly impact customer satisfaction, deliverability, and business success as we bring on larger enterprise accounts.

How You Will Make a Difference:

• Lead a team of engineers building and scaling Klaviyo's email delivery infrastructure


• Own and drive the architecture of key components in the email pipeline


• Design and implement scalable, high-throughput services in Go and Python


• Build systems that manage message queues and ensure reliable email delivery at scale


• Contribute directly to architecture and code, driving best practices and quality


• Collaborate cross-functionally to ensure the highest standards of performance, reliability, and deliverability


• Grow and mentor engineers while helping shape the future of email infrastructure at Klaviyo


• Transform workflows by putting AI at the center, building smarter systems and ways of working from the ground up

Who You Are:

• 8+ years of engineering experience with strong backend and systems design skills


• Proficient in Go and Python (required)


• Comfortable coding and reviewing complex systems — this is a hands-on role


• Experienced working with high-throughput distributed systems


• Familiar with message queues (e.g., Pulsar, Kafka, RabbitMQ, SQS)


• Skilled in system design and scaling infrastructure using AWS


• Bonus: Experience with email infrastructure, MTAs, deliverability, or mailops


• Clear communicator and collaborative team player


• Able to thrive in a hybrid team(with some remote team members) and deliver in a high-autonomy environment


• 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.

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