Software Engineer Intern (Summer 2027)

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, our Engineering teams build scalable, high-performance systems that power both our product and the infrastructure behind it. As a Software Engineering Intern, you'll be part of a fast-paced, collaborative team whose work reaches thousands of customers worldwide. You won't just be writing code. You'll be solving hard problems, shaping how users experience our product, and learning from engineers who've been doing this for a while.

This internship is your shot to put your software development skills to work in production. You'll be embedded on one of our engineering teams (see overviews below), take on projects that matter to our customers, and build a technical foundation as you make connections across the business.

Our interns come from all kinds of coding backgrounds, but they all share one thing: they're excited to build, own, and scale features end-to-end, from scratch. You'll work alongside experienced engineers, take on hard technical problems, and ship code that supports Klaviyo's mission. We're an AI-first company, so you'll be expected to use AI tools to support your work, learn faster, and do your best work here.

How you'll make an impact

• Own features that our 180K+ paying customers rely on daily to reach their consumers and grow their business.

• Take responsibility for the mission, technical direction, and operation of projects with immediate impact.

• Own the full lifecycle of your code: writing it, testing it, shipping it, and making it better over time. Ownership is expected here, not just encouraged.

• Build and ship features that meet a high bar and grow your technical skills while you do it.

• Get hands-on debugging real issues, both locally and in production.

• Contribute to documentation and support your team during incidents (real-world problems teach you things a tutorial never will).

• Work closely with your teammates: ask questions, share ideas, and get better by taking feedback seriously.

• Learn to use the right tool for the job, lean into AI, and keep looking for ways to make things better.

• Put AI at the center of how you work to move faster. Build smarter systems and better workflows from the ground up.

Who you are

• At least one previous software engineering internship or co-op, with hands-on software development experience