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Senior Backend 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.

About Klaviyo

Klaviyo is a unified customer platform for email, SMS, and more that helps businesses of every size own their marketing, customer relationships, data, and destiny. Klaviyo has helped hundreds of thousands of businesses grow by fostering customer relationships and generating billions of dollars in eCommerce purchases. In 2022, Klaviyo was recognized by Glassdoor as a Best Place to Work in the U.S. small and medium company category and by Comparably as one of the Best Engineering Teams and Product & Design Teams. 

About the Team

Our engineers are organized into a series of product pillars, where multiple teams are contributing to the goals of a larger mission. This role sits within the Intelligence pillar which focuses on two main goals: helping customers understand where their business is currently, as well as helping them predict and plan for where they want to grow in the future. 

We are proud of our data and our goal is to harness that wealth of numbers and present them to our customers in a way that is actionable, intuitive, and accessible. In the Intelligence pillar, software engineers and data scientists work together to take ideas from inception to new data-powered features.

About the Role:

As a Senior Software Engineer on our Reporting team, you will play a big role in our Unified Stats project which is a big initiative for the team. Unified Stats has been built but needs to be fleshed out. This person will be creating a backend common calculation framework so that metrics between different reports across the platform are all displayed in the same way.

How you’ll make an impact:

  • Wholly owning features that thousands of our customers rely on daily to reach 100,000,000+ of consumers to drive their business forward
  • Working with our highly scalable real-time data pipeline that processes billions of events weekly across data sets growing to petabyte scale
  • Working on a deep analytics system that provides insight into hundreds of terabytes of data
  • Be responsible for the mission, technical direction and operations of projects that have immediate impact
  • Helping architect and design robust and high performance data processing and storage systems leveraging new databases to serve different internal and external use cases; contribute to open source data processing technologies

Technologies we use (not comprehensive):

  • Python, React, Javascript
  • numpy, MySQL, Redis
  • Django, sqlalchemy
  • ECS, Aurora, Kafka, Pulsar

What you’ll need:

  • 5+ years of professional experience as a software engineer
  • Experience working with both monolithic and microservices architectures
  • Experience with maintaining and improving performance, reliability, and scalability of systems
  • Be a leader in system design; provide technical direction and mentorship for more junior team members
  • Customer-focused mentality and a focus on features that will deliver real value
  • Ability to collaborate cross-functionally with product teams and incorporate feedback from customers and internal stakeholders into development process

Nice to have:

  • Experience working with messaging systems like Pulsar, Kafka, RabbitMQ, or SQS
  • Interest in statistics and data science

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 diversity and to a policy of equal employment opportunity and non-discrimination. We do not discriminate on the basis of race, color, religion, national origin, age, sex, marital status, ancestry, physical or mental disability, veteran status, gender identity, sexual orientation or any other characteristic protected by applicable law.

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