Full Stack Software Engineer II

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 careers.klaviyo.com to see how we empower creators to own their own destiny.
About the Role
Klaviyo is looking for Full Stack Engineers to support key initiatives that enhance our product offerings and drive company growth. In this role, you'll play a critical part in delivering end-to-end solutions using both front-end and back-end technologies. You'll improve existing products and develop new capabilities that push the boundaries of what's possible for our customers.
As a Software Engineer II, you'll tackle complex challenges, explore multiple solutions, and weigh business and technical trade-offs to determine the best path forward. You'll actively contribute to team discussions and help shape important technology decisions. You'll also be responsible for shipping well-designed, thoroughly tested solutions that prioritize reliability and performance.
What We're Looking For

• A proven track record of building high-quality products and systems, with a focus on writing clean, maintainable code
• 3+ years of experience in a software engineering role
• Experience building end-to-end software solutions or deep experience with both front-end and back-end technologies
• Familiarity with code reviews and leading or participating in robust testing practices
• Experience working in agile, fast-paced environments

Nice to Have

• Experience with Python and related technologies
• Experience with React and related technologies
• Background in digital marketing or customer data software
• Exposure to machine learning concepts or applications
• Experience building cloud-native solutions, ideally on AWS

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
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. Please visit Klaviyo Rewards to find out more about our Total Rewards package.
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:
$120,000 - $180,000 USD
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.
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.
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