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# Senior Software Engineer - Profiles, Lists and Segments

- **Company:** Klaviyo
- **Location:** Boston, MA, United States
- **Experience:** Expert
- **Salary:** $148,000.0 - $222,000.0
- **Contract:** Permanent contract
- **Skills:** HTML, JavaScript (Programming Language), Application Programming Interfaces (APIs), Artificial Intelligence, Amazon Web Services, Amazon Elastic Compute Cloud, Amazon S3, Automation of Tests, Cascading Style Sheets (CSS), Code Review, DevOps, Django Web Framework, Design of User Interfaces, Human-Computer Interaction, Python (Programming Language), MySQL, Systems Development Life Cycle, RabbitMQ, Redis, Software Engineering, TypeScript, ReactJS, Cypress (Programming Language), Pytest, Integration Tests, Graphql, Front End Software Development, React Redux, Restful APIs, Terraform
- **Published:** October 29, 2026
- **Apply:** https://www.careerbuilder.com/job-details/senior-software-engineer-profiles-lists-and-segments-boston-ma--a1f1535c-1c8d-40b9-9551-1b0acae59efd

## About the Role

Software Engineering, Customer/Client Research, Data Science, Scalable System Development, Software Engineering, User Interface/Experience (UI/UX), Customer Relations, Customer Experience, Product Design, Mentoring, * 5+ years of experience in full-stack development with strong hands-on skills in React, Redux, JavaScript, HTML, and CSS, along with familiarity with general web best practices.

 * Has a track record of delivering and shipping work powered by or accelerated through AI.
 * Experience conducting code reviews and running a robust testing cycle using automated testing practices and frameworks, including end-to-end and integration tests (e.g., cypress, pytest).
 * Experienced with RESTful and GraphQL APIs, and evolving APIs and data models to support product success.
 * You take ownership of your work-from requirements and edge cases to implementation and testing-and are motivated by solving tough problems with others.
 * Proven track record of leading complex, multi-quarter projects involving cross-team collaboration and being accountable for their outcomes

Technologies We Use (not exhaustive):

 * React, TypeScript, Redux
 * Python, Django
 * Amazon Web Services (EC2, RDS, Aurora, S3, etc.), Terraform, and other DevOps tools
 * MySQL, RabbitMQ, Redis, ProxySQL

## Description

As a Senior Software Engineer on the team, you'll play a key role in designing and building scalable systems that power how customers manage and activate their data. Partnering closely with product managers, data scientists, and other platform teams, you'll help define scope, translate complex data and UX problems into practical implementations, and build intuitive workflows that give customers confidence in their audiences. This role leans frontend, with a strong focus on crafting thoughtful, reusable components and seamless user experiences using technologies like TypeScript, React, Python, and Django. There are ample opportunities for growth given the scope of this role and the team's central role in Klaviyo's product.

How You Will Make a Difference:

 * You will be a core member of the PLS team, working on impactful customer-facing features that will make our product the best in the industry.
 * You will work on creating easy-to-use editors that are highly performant.
 * You will work closely with Product, Design, and Data Science to provide the best experience for our customers.
 * You will mentor team members and drive initiatives that help the team learn new skills.