Hiring: Senior Software Engineer - Growth Company: Klaviyo Location: Boston, MA Job Posted Time: 2026-09-10 13:06:39 Target Skills & Keywords : A/B Testing, AWS, Ansible, Aurora, Cassandra, Django, EC2, HTML, JavaScript, MySQL, Packer, Python, RDS, RabbitMQ, React, Redis, Terraform, TypeScript, User Experience About the job Required Skills: •How You Will Make a Difference •Strategically drive technical design and lead the implementation of high-impact user-experience improvements across the Klaviyo product, focusing on areas critical to new customer success and adoption. •Own the entire project lifecycle, working through ambiguity and requirements refinement to execution and delivery. •Own the end-to-end experimentation process, including contributing to the definition of strategy, architecting and implementing A/B tests to validate product hypotheses, and interpreting data to drive significant iterative improvements. •Be accountable for the quality and operational health of the features you deliver. •Serve as a technical leader and liaison, collaborating proactively with partners across teams to define and prioritize key technical initiatives to shape the long-term product roadmap. •Take a lead role in mentoring and providing technical guidance to other engineers on the team, elevating our experimentation, development, and operational practices, ensuring contributions consistently leave the product area better than when you found it. •Define the architectural approach and technical strategy for your area of responsibility, anticipating scalability and reliability needs, including leveraging AI agents in our work and delivery, ensuring the solution is robust, scalable, and adheres to best practices for security, performance, and maintainability. Qualifications: •Have an extensive background in full stack software engineering, demonstrating deep understanding of Klaviyo’s systems and the ability to architect, deliver, and maintain software with an emphasis on high-scale, user-facing features, and their supporting APIs and infrastructure. •Demonstrated ability to drive technical strategy and improvement using a data-driven mindset, leading to measurable business results and upholding best practices. •Demonstrated technical experience in using and championing AI-driven software delivery practices and methods, a passion for continuous learning and mentoring, and the ability to work productively through others to set them up for project success. •Thrives in an entrepreneurial type environment that is customer focused and strategic, while bringing clarity and technical stability to ambiguous challenges and prioritizing work that enables the team to move faster. •Technologies We Use (not Exhaustive) •Amazon Web Services, Terraform, Ansible, Packer, and other DevOps tools •We use Covey as part of our hiring and / or promotional process. For jobs or candidates in NYC, certain features may qualify it as an AEDT. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications. We began using Covey Scout for Inbound on April 3, 2025. •Please see the independent bias audit report covering our use of Covey here •It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability. Compensation: •$148,000 - $222,000 / year Interested candidates, please apply directly through the job posting on company's career page or try via AI auto apply on this platform. Don't miss this opportunity to join a forward-thinking team!