Software Engineer II, Test Frameworks & Tooling

Direct Impact on Stability: Your work is the primary line of defense against Sev 1 incidents. When the platform stays up and customers stay happy, it is because of the systems you help maintain.

Full-Stack Visibility: Because you own the E2E suite, you will gain a deep understanding of how our entire ecosystem fits together, from frontend UI components to complex backend microservices.

Autonomy and Growth: While we provide the vision, you provide the execution. You will have the space to own your work end-to-end, propose technical improvements, and see your suggestions implemented company-wide.

High-Leverage Work: You are not just building one feature for one customer. You are building the tools that hundreds of your fellow engineers use every single day to do their jobs better.

Who You Are:

Analytical Problem Solver: You have 2+ years of software engineering experience with a focus on writing clean, maintainable code. You excel at debugging complex issues and performing root-cause analysis, using those learnings to implement systemic improvements that prevent future regressions.

Quality Advocate: You find satisfaction in a well-organized test suite. You understand that testing is a fundamental part of the development lifecycle, not an afterthought.

Technical Generalist: You are comfortable working across the stack. Whether it is debugging a React component in an E2E test or optimizing a Python integration test, you are ready to dive in.

AI-Forward Thinker: You are excited about the intersection of AI and Software Quality. You are eager to help us leverage AI to automate test generation, identify flaky patterns, and accelerate the overall development lifecycle.

Ownership Mindset: You do not just wait for tickets. You look for ways to make things better. You take pride in owning a project from the initial PR to its successful deployment and monitoring.

CI/CD Familiarity: You have experience with, or a strong desire to learn, CI/CD tools and understand how automated testing fits into a modern deployment pipeline.

Technologies we use (not exhaustive):

Backend: Python, Django, Go

Frontend: React, TypeScript, JavaScript

Testing Frameworks: Playwright, Cypress, Pytest, Jest

Infrastructure and CI: AWS, Kubernetes, Terraform, Helm, Buildkite

Data: MySQL, Redis, Kafka

AI Tools: Integration with Claude, Cursor, Copilot, or internal AI enablement frameworks

Massachusetts Applicants: 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.

Our salary range reflects the cost of labor across various U.S. geographic markets. The range displayed below reflects the minimum and maximum target salaries for the position across all our US locations. The base salary offered for this position is determined by several factors, including the applicant’s job-related skills, relevant experience, education or training, and work location.

In addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility.

Your recruiter can provide more details about the specific salary/OTE range for your preferred location during the hiring process.

This role may require up to 10% travel for purposes such as new hire onboarding, client or partner work if applicable, team meetings, and industry events. Travel is coordinated in advance.

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.

AI fluency at Klaviyo includes responsible use of AI (including privacy, security, bias awareness, and human-in-the-loop). We provide accommodations as needed.

By participating in Klaviyo’s interview process, you acknowledge that you have read, understood, and will adhere to our Guidelines for using AI in the Klaviyo interview Process. For more information about how we process your personal data, see our Job Applicant Privacy Notice.

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.