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Senior Lead Software Engineer

  • Boston, MA
  • 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 to see how we empower creators to own their own destiny.

As a Senior Lead Software Engineer joining the Core Data team you can expect to be deeply involved in technical discussions on how we scale our systems, roll out new features, and grow the team. The Core Data team encapsulates half a dozen different critical data storage and processing functions upon which significant application features rely. The Core Data teams are committed to providing responsive, reliable, and robust services that store user profile information, user attributes, lists and segments, catalogs, and coupons, and support our customers’ ability to extract full value from their data.


As a Senior Lead Engineer, you will serve as the technical lead, hands-on developer and an individual contributor with an architectural and technical design mindset for a core piece of our platform product. You will be responsible for designing, building, and maintaining systems to support multiple core product areas in Klaviyo. 

As a Senior Lead Engineer you will help drive the team forward and set the technical direction of these systems. You will work with a cross functional team to help refine feature specifications, write technical design documents, create system infrastructure, write high quality code, and operate large scale systems in production. You will also review other engineer’s designs and code, and provide technical mentorship to other engineers on the team and in the broader engineering organization.

Team Tech Stack (Not Exclusive)

  • Python
  • Django
  • React
  • MySQL
  • ClickHouse
  • ProxySQL
  • Redis
  • Memcached
  • RabbitMQ
  • Kafka

How You Will Make a Difference 

  • Provide technical leadership to drive architectural decisions across multiple teams and provide solutions for complex problems around scalability, throughput, performance, etc.
  • Strive towards a cohesive technical vision across multiple roadmap items that are built across multiple teams.
  • Defines technical strategy within their scope and executes to improve the area's products, infrastructure, or processes.
  • Mentors multiple engineers to develop new technical leadership for the company.

Who You Are 

  • Have 10+ years of experience and have architected, built, and delivered at least one complex system.
  • A comprehensive understanding of complex backend architectures and their core pieces, such as service models, protocols, reliability, deployment, and capacity.
  • Demonstrated experience to understand the tradeoffs to technical design decisions, risk assessment and mitigation activities.
  • Have proven that you can build & scale complex distributed systems including solving problems in sustainable ways, balancing pragmatic development with ideal architecture, breaking through technical obstacles with vigor, and leading teams through crises by working side by side with them in the trenches.
  • Like working on small, autonomous lean teams. At Klaviyo, you will have ownership of features, but you'll collaborate with everyone to make sure we produce the right solution.

Get to Know Klaviyo

Klaviyo is a world-leading marketing automation platform dedicated to accelerating revenue and customer connection for online businesses. Klaviyo makes it easy to store, access, analyze and use transactional and behavioral data to power highly-targeted customer and prospect communications. The company's hybrid customer-data and marketing-platform model allows companies to grow by fostering direct relationships with customers, without giving up their valuable data to popular big-tech ad platforms. Over 265,000 innovative companies like Unilever, Custom Ink, Living Proof and Huckberry sell more with Klaviyo. Learn more at .

If you are a California, Colorado, Rhode Island, Washington, New York City, or Jersey City resident and this role is a remote role, you can receive additional information about the compensation and benefits for this role, which we will provide upon request. Requests can be submitted here . Additional information regarding benefits can be found at .

      • Klaviyo is committed to a policy of equal opportunity and non-discrimination. We do not discriminate on the basis of race, ethnicity, citizenship, national origin, color, religion or religious creed, age, sex (including pregnancy), gender identity, sexual orientation, physical or mental disability, veteran or active military status, marital status, criminal record, genetics, retaliation, sexual harassment or any other characteristic protected by applicable law.


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