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Senior Software Engineer, Full Stack

  • 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.

At Klaviyo, we love tackling tough engineering problems and look for Engineers who specialize in certain areas but are passionate about building, owning & scaling features end to end from scratch and breaking through any obstacle or technical challenge in their way. We push each other to move out of our comfort zone, learn new technologies and work hard to ensure each day is better than the last.

Klaviyo operates a real-time data platform written in Python and built for massive scale on Amazon Web Services (AWS). Engineers come to Klaviyo with experience in a variety of languages and from a number of disciplines.

We are seeking a frontend-leaning full-stack Senior Software Engineer who is passionate about using cutting-edge open source frameworks with emerging technologies. You’ll have the opportunity to be on the forefront of driving a major transformation within Klaviyo.

Technologies we use (not exhaustive):

  • React, Typescript, Webpack, Fastly
  • Python, Django
  • RabbitMQ, Celery, Kafka, Apache Pulsar
  • MySQL, Redis, Memcached
  • Graphite, statsd, Grafana
  • AWS, Kubernetes, Terraform, Docker, Jenkins, and other modern DevOps tools

How You'll Make a Difference

  • Own customer-facing features that tens thousands of our customers rely on daily to reach 4B+ of consumers to drive their business forward
  • Lead the development of customer-facing components in complex distributed data processing systems
  • Work with a team of developers with deep experience in distributed microservices and full stack systems
  • Own the technical design and development of cross-functional, multi-platform application systems
  • Establish expertise in multiple internal and industry practices, patterns, tools, languages, and processes
  • Lead and mentor engineers within your organization on frontend best practices

Who You Are

  • Be proficient in both frontend and backend
  • Extensive frontend engineering experience
  • Experience working in React
  • Experience developing application APIs (e.g. REST, GraphQL, JSON Schema, or JSON:API, etc.)
  • Experience working with distributed systems is preferred
  • Experience working with cloud technologies (AWS, GCP, Azure, etc.)
  • Experience with custom frontend build systems + tooling (e.g. Webpack, Babel, TypeScript, ESLint, Jest, Jenkins, CDNs, etc.)
  • Having established best practices in how a company writes, tests, and deploys frontend code
  • Enjoy working on small, autonomous agile teams. 
  • Enjoy shipping code early and often in an agile fashion, pairing with product management, business stakeholders, and other engineers to craft better software.

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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