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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 machine learning-powered features.

About the Role:

The Predictive Analytics team builds features that help our customers understand and predict their customers' behavior. Features such as Predicted Customer Lifetime Value and Expected Date of Next Order give Klaviyo users confidence to be able to engage with their audience effectively. Check out our Data Science podcast to learn more!

As a Senior Software Engineer for Predictive Analytics, you will collaborate with product, design, and data science teams to conceptualize and build a new suite of tools for our customers as well as up-level existing tools. You’ll help set the direction of this new team by working to establish predictive analytics as a valuable tool for our customers’ marketing strategy. Klaviyo users grow by leveraging these tools to deliver the right communication to the right people at the right time. 

You will be a leader in the design, development, and maintenance of systems that ingest and process billions of customer events each month. In addition to your engineering work, you will contribute to all phases of the feature development process including strategizing with product managers about feature specifications, and working with designers to continually refine aspects of the user experience.

We have only scratched the surface of the possibilities for predictive analytics at Klaviyo and you’ll be a thought partner helping to build the direction of the team, the future roadmap, and user experience.

How you’ll make an impact:

  • Build data pipelines that ingest and process billions of customer events
  • Collaborate with data scientists to deploy machine learning solutions powered by billions of customer events
  • Deploy features that help more than a hundred thousand companies communicate effectively with their customers and grow their business
  • Contribute to the back-end development of features
  • Be a leader in system design; provide technical direction and mentorship to more junior team members

Technologies we use (not comprehensive):

  • Python
  • numpy, pandas, sklearn
  • Django, sqlalchemy
  • ECS, Aurora, Kafka, SQS

What you’ll need:

  • 4+ years of professional experience as a software engineer
  • Experience leading or co-leading substantial engineering projects with measurable impact
  • Experience working with both monolithic and microservices architectures
  • Experience with maintaining and improving performance, reliability, and scalability of systems
  • 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
  • A bachelor’s or advanced degree in computer science, applied math, statistics or other relevant quantitative discipline, or equivalent industry experience

Nice to Have :

  • Experience working with messaging systems like 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 Colorado or New York 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 here .

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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