Full-stack Software Engineer Co-op (Spring 2026)

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.

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 are close but not an 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 our Co-op

At Klaviyo, our Engineering team builds the foundational technologies that power how brands grow through owned marketing. As a Full-stack Software Engineering Co-op, you'll be part of a fast-paced, collaborative environment where your work directly impacts thousands of customers worldwide. You won't just be writing code-you'll be solving real problems, shaping user experiences, and learning from seasoned engineers across our engineering organization.

This co-op is an opportunity to apply your software development skills in a production environment. You'll be embedded within one of our engineering teams (see overviews below) and work on meaningful projects that make a real difference to our customers, all while building a strong technical foundation and connections across Klaviyo.

Co-ops come to Klaviyo with experience in a variety of coding languages, but they are all passionate about building, owning, and scaling features end-to-end from scratch. You'll work alongside seasoned engineers, break through complex technical challenges, and gain hands-on experience contributing to real products that support Klaviyo's mission. We operate a real-time data platform coded in Python built for massive scale on Amazon Web Services (AWS). As an AI-first company you will be encouraged to use AI tools to support your work, accelerate learning, and succeed in your role.

How You'll Make an Impact

• Own features that our 150K+ paying customers rely on daily to reach their consumers to drive their business forward
• Be responsible for the mission, technical direction and operations of projects that have immediate impact
• Architect and design robust and high performance data processing and storage systems leveraging new databases to serve different internal and external use cases
• Craft our highly scalable real-time data pipeline that processes billions of events weekly across data sets growing to petabyte scale
• Work on a deep analytics system that provides insight into hundreds of terabytes of data
• Transform workflows by putting AI at the center, building smarter systems and ways of working from the ground up.

What We're Looking For

Co-op Logistics

Engineering at Klaviyo

At Klaviyo our engineering teams are broken into pillars to streamline the work.

Growth : Reduce friction across the board for our customers, increase cross-sells, and help us launch into new geographies and verticals

Marketing Platform : Give marketers the tools they need to engage with their customers, be successful, and know where they stand

Mobile Channels and Messaging Infrastructure : Own the growth of our mobile channels and all messaging infrastructure

Data Infrastructure : Empower our internal teams and customers to get the best out of our data and underlying capabilities

Core Infrastructure : Empower our internal engineering, sales, and service teams to be as effective as possible

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.

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 :

$53-$53 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.

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

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. You can find our Job Applicant Privacy Notice here.

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.