Senior Software Engineer, Onboarding & Growth

Klaviyo Inc.; Boston (MA); Hybrid; USD 148,000 - 222,000; Full time

Job summary

Klaviyo Inc. is seeking a seasoned software engineer for the Onboarding-focused Product Expansion / Activation team in Boston. You will lead design and delivery of high-impact onboarding experiences for new customers, using data-driven methods and A/B testing to validate hypotheses and improve adoption.

You will mentor peers, define scalable architectures, and collaborate across teams to shape the product roadmap while working on-site at our Boston headquarters five days a week.

Qualifications

• Extensive background in full stack software engineering with emphasis on high-scale, user-facing features and their APIs.
• Proven ability to drive technical strategy using a data-driven mindset.
• Experience championing AI-driven software delivery practices and mentoring.
• Experience driving A/B testing strategies to improve UX and onboarding.
• Ability to work with cross-team partners to shape long-term product roadmap.

Responsibilities

• Drive the technical design and lead implementation of high-impact UX improvements across the product for new customers.
• Own end-to-end experimentation, define strategy, architect and implement A/B tests, interpret data for improvements.
• Serve as a technical leader and liaison across teams to prioritize key initiatives.
• Mentor and provide technical guidance to engineers to improve experimentation and delivery practices.
• Define architectural approach and strategy for scalability and reliability, including AI agent usage.
• Work from Boston HQ 5 times per week.

Skills

Full stack engineering

Data-driven mindset

AI-driven software delivery

Mentoring

A/B testing

Tools

HTML

TypeScript

JavaScript

React

Python

Django

MySQL

Cassandra

RabbitMQ

Redis

AWS

Terraform

Ansible

Packer

Job description

Klaviyo Inc. is seeking a seasoned software engineer for the Onboarding-focused Product Expansion / Activation team in Boston. You will lead design and delivery of high-impact onboarding experiences for new customers, using data-driven methods and A/B testing to validate hypotheses and improve adoption.

You will mentor peers, define scalable architectures, and collaborate across teams to shape the product roadmap while working on-site at our Boston headquarters five days a week.