Software Engineer I

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.

As a Software Engineer I at Klaviyo, you’ll join a team that loves programming and the excitement of building products people actually use. You’ll learn how to balance solving problems quickly with writing code that lasts. This is a growth-oriented role designed for engineers early in their careers — you’ll sharpen your technical skills, collaborate with experienced teammates, and contribute meaningfully on key projects, initiatives, and team goals.

Our engineering teams are focused on building scalable, high-performance systems that power both key product experiences and internal platforms. In this role, you’ll gain exposure across the stack — from frontend to backend — while learning modern infrastructure and engineering best practices.

You’ll be given the support to execute work independently, implement and test software, document, deploy, and maintain services in production. If you’re excited to launch your engineering career where you can build systems that matter while learning in a fast-paced, product-driven environment — this role is for you.

How You’Ll Make A Difference:

• Learn to own the full lifecycle of your code — from writing and testing to deploying, monitoring, and improving it over time.
• Build and ship features that follow best practices and meet team goals, while growing your technical skills.
• Gain hands-on experience debugging issues in both local and production environments.
• Contribute to documentation and help support your team during incidents, learning from real-world challenges.
• Collaborate closely with teammates, ask questions, share ideas, and grow by embracing feedback.
• Transform workflows by putting AI at the center, building smarter systems and ways of working from the ground up.

Who You Are:

• 2 previous experiences in high impact internship/co-op roles working with production-level code
• Currently pursuing a degree in Computer Science, Engineering, Data Science, Math/Statistics or related field
• Graduating in December 2025 or May/June 2026
• Experience with some of these technologies and languages:
• Python, Django, Typescript, React
• MySQL, Cassandra, Clickhouse, Kafka, Redis
• Amazon Web Services (EC2, RDS, Aurora, etc.) Terraform
• Build strong cross-functional relationships and partner effectively with colleagues to achieve impactful results.
• Demonstrate adaptability and learning agility by quickly absorbing new information, applying it effectively, and adjusting to evolving circumstances.
• Embrace Klaviyo’s “always learning” culture that fosters learning at every level, constantly pushing yourself to be a better engineer 
• You’ve already experimented with AI in work or personal projects, and you’re excited to dive in and learn fast. You’re hungry to responsibly explore new AI tools and workflows, finding ways to make your work smarter and more efficient. 

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. 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:$96,000—$144,000 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.

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.