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Senior Software Engineer - Flows Platform

  • 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 the Team 

The Flows Team enables users to automate their marketing by allowing users to create their own workflows. Users set up these workflows via a drag and drop visual builder. After setting up the triggering criteria, customers enter these workflows in real time and can receive email, SMS, and push notifications; or trigger generic outbound webhooks to integrate with other services. The tools we provide are robust enough that we’re often surprised and delighted by the inventive workflows our users make-- some have even made workflows to send physical mail!

Flows is a full-stack team, and usability and scalability are top of mind for the Flows Team. We strive to create the most intuitive and accessible experience for users to set up their workflows..

Future feature work for our team includes creating new ways to trigger workflows based on what happens to an item in an ecommerce store, leveraging our generic webhook action to create more plug and play connections to external services, and to enhance our visual flow builder experience.

About the Role 

This is a truly full-stack role, delivering products that are both customer-facing and high-scale. We are a highly collaborative team. We work closely with Product and Design to shape features from inception to release. As our team quickly grows, there is plenty of opportunity for leadership as an Individual Contributor or Manager.

How You will make an Impact 

Incoming members to the Flows Team will be responsible for building the foundation of how we scale internally at Klaviyo. You will have an opportunity to make a major impact on the direction and priorities of the team.

Projects on our roadmap have a good mix of front end and backend technologies.  On the back end, our processing pipeline handles over 60 million actions a day and sends up to 25+ million email/messages on an average day. We’ve been able to handle this load thanks to good engineering and system design, and we have plenty of ideas to make our pipeline even faster and more powerful. There are plenty of opportunities for engineers on our team to grow on the backend as well as the frontend

Technologies we use (not exhaustive):

  • Python, Django, React, Redux, Celery, MySQL, RabbitMQ, Cassandra, Redis
  • Amazon Web Services (EC2, RDS, Aurora, etc.), Grafana, Terraform, Kuberentes, Splunk, Jenkins, and other modern DevOps tools

What we are looking for 

  • 5-7+ years of experience in a software engineering discipline
  • Significant experience with full stack application development
  • Expertise working with Python on the backend to develop applications
  • Experience working with React on the Frontend 
  • Experience working with large-scale system design and operations
  • Experience working with AWS or any similar cloud provider 
  • Experience collaborating closely with Product Managers to deliver customer-facing features
  • Experience debugging performance issues and improving application performance
  • Focus on high-quality, scalable, and extensible code
  • Proven experience with being a coach and a mentor for team members and helping them grow

Nice to Have

  • Experience building and deploying automation solutions
  • Experience with Agile/Scrum, and an interest in improving processes

Get to Know Klaviyo

We’re Klaviyo (pronounced clay-vee-oh). We empower creators to own their destiny by making first-party data accessible and actionable like never before. We see limitless potential for the technology we’re developing to nurture personalized experiences in ecommerce and beyond. To reach our goals, we need our own crew of remarkable creators—ambitious and collaborative teammates who stay focused on our north star: delighting our customers. If you’re ready to do the best work of your career, where you’ll be welcomed as your whole self from day one and supported with generous benefits, we hope you’ll join us.

Upon request, you can receive additional information about the compensation and benefits for this role. 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.

You can find our Job Applicant Privacy Notice here .

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