AI Engineer II

<div class="content-intro"><p><em>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 <a class="_ymio1r31 _ypr0glyw _zcxs1o36 _mizu194a _1ah3dkaa _ra3xnqa1 _128mdkaa _1cvmnqa1 _4davt94y _4bfu18uv _1hms8stv _ajmmnqa1 _vchhusvi _kqswh2mm _ect4ttxp _syaz13af _1a3b18uv _4fpr8stv _5goinqa1 _f8pj13af _9oik18uv _1bnxglyw _jf4cnqa1 _30l313af _1nrm18uv _c2waglyw _1iohnqa1 _9h8h12zz _10531ra0 _1ien1ra0 _n0fx1ra0 _1vhv17z1" href="http://klaviyo.com/careers" data-renderer-mark="true">klaviyo.com/careers</a>&nbsp;to see how we empower creators to own their own destiny.</em></p></div><p>Job Title:&nbsp;<strong>Software Engineer II - Marketing Agent</strong></p> <p>Location: <strong>Boston, MA (Hybrid 3x week)</strong></p> <p>At Klaviyo, we believe the future of software lies not in productivity tools for human users but in systems that do the hard work for them. We’ve built the infrastructure and applications that power the interface between businesses and consumers — supporting over 183,000+ customers, billions of consumer profiles, and hundreds of billions of customer interactions. Now, we’re building the next generation of AI agents that can automatically create, execute, and optimize marketing and customer experience strategies for any business.</p> <p>As a Software Engineer II on Klaviyo's Marketing Agent team, you'll be at the forefront of one of the most impactful bets we're making — building an AI-powered system that autonomously creates and executes high-stakes marketing strategies on behalf of thousands of customers. This isn't backend plumbing: the work you ship directly drives revenue for the businesses that rely on Klaviyo every day. Partnering closely with product managers and technical product owners, you'll shape the scope of what's possible, turn ambitious ideas into production reality, and craft tools so intuitive they feel like superpowers to the marketers using them.</p> <p>This role is primarily backend, with a strong focus on crafting robust and maintainable AI powered systems that deliver high quality strategies and marketing content that’s ready to use to our customers. There are ample opportunities for growth given the scope of this role and the team’s central role in Klaviyo’s product.</p> <p>&nbsp;</p> <p><strong>How you’ll make a difference:</strong></p> <ul> <li>You will dramatically increase ROI for Klaviyo customers by automating most of the marketing process for them.</li> <li>You will lead and design the next generation of agentic systems at Klaviyo, pushing the frontier of AI capabilities.</li> <li>You will collaborate with AI Engineers and AI Infra Engineers to ensure our system consistently produces high quality outputs at low latency.</li> <li>You will leverage your experience to mentor and level up junior team members on engineering best practices and patterns.</li> <li>You will transform workflows by putting AI at the center, building smarter systems and ways of working from the ground up.</li> </ul> <p>&nbsp;</p> <p><strong>Who you are:&nbsp;</strong></p> <ul> <li>A proven track record of building high-quality products and systems, with pride in writing clean, high-quality code.</li> <li>3+ years of experience in a software engineering role.</li> <li>Experience leading projects and being accountable for their outcomes.</li> <li>Experience mentoring team members or driving initiatives that help the team learn new skills.</li> <li>Experience conducting code reviews and running a robust testing cycle.</li> <li>Experience working in agile, fast-paced environments.</li> <li>Proficient in Python and modern web stack components such as FastAPI, Django, MySQL, Postgres.</li> <li>Experience working in cloud environments (AWS preferred).</li> <li>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.</li> </ul> <p>&nbsp;</p> <p><strong>&nbsp;Nice to have:&nbsp;</strong></p> <ul> <li>Prior work