Software Engineer II, Test Frameworks & Tooling

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 klaviyo.com/careers to see how we empower creators to own their own destiny.Why You Should Join the Test Frameworks and Tooling TeamEngineering confidence is our primary product. We are not testers, but rather infrastructure engineers building the sophisticated automation and CI/CD frameworks that make deploying to production a non-event. Our mission is to architect the systems, repository standards, and automated guardrails that empower every engineer in the company to ship at terminal velocity with total confidence. By building the foundational tools that guarantee production readiness, you will play a direct role in driving Sev-1 incidents toward zero and ensuring that our organization can move fast without the fear of breaking things.What You'll Achieve: Key ResponsibilitiesAs a core member of the team, you will own the execution of critical projects and contribute to the evolution of our testing ecosystem:Own and Enhance Frameworks: Take ownership of our integration and E2E testing frameworks across both backend and frontend stacks. You will ensure they are fast, reliable, and easy for other teams to adopt.CI/CD Integration: Contribute to how we execute tests within our CI system. You will focus on optimizing feedback loops so engineers know exactly where they stand in minutes.Establish Standards: Help define and implement general rules for our repositories, ensuring consistency in how unit tests are written and how code quality is measured.Scalable Feature & Coverage Contribution: Actively develop new tools that simplify complex testing scenarios while identifying and backfilling critical testing gaps at scale. You will build systems for data mocking and service isolation that ensure high-fidelity coverage across our most complex application flows.AI-Driven Quality Innovation: Help lead the charge in leveraging AI to accelerate our testing lifecycle. You will explore and implement AI-powered tools for automated regression detection, flaky test analysis, and intelligent test generation to decrease time-to-completion for features.Collaborative Problem Solving: Partner with feature teams to troubleshoot flaky tests and identify gaps in our current coverage, making proactive suggestions to improve our overall safety net.Operational Excellence: Monitor the health of our test suites and CI pipelines, taking pride in maintaining a stable and performant environment for the entire engineering organization.What Makes This Role ExcitingDirect 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, GoFrontend: React, TypeScript, JavaScriptTesting Frameworks: Playwright, Cypress, Pytest, JestInfrastructure and CI: AWS, Kubernetes, Terraform, Helm, BuildkiteData: MySQL, Redis, KafkaAI Tools: Integration with Claude, Cursor, Copilot, or internal AI enablement frameworksMassachusetts 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.Base Pay Range For US Locations:$116,000—$174,000 USDThis 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 KlaviyoWe’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.IMPORTANT NOTICE: Our company takes the security and privacy of job applicants very seriously. We will never ask for payment, bank details, or personal financial information as part of the application process. All our legitimate job postings can be found on our official career site. Please be cautious of job offers that come from non-company email addresses (@klaviyo.com), instant messaging platforms, or unsolicited calls.By clicking "Submit Application" you consent to Klaviyo processing your Personal Data in accordance with our Job Applicant Privacy Notice. If you do not wish for Klaviyo to process your Personal Data, please do not submit an application.You can find our Job Applicant Privacy Notice here and here (FR).