Senior AI Engineer

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 to see how we empower creators to own their own destiny.

At Klaviyo, we believe the future of software lies not in productivity tools for human users but in software that can run and optimize itself based on outcome or reward metrics. We've built the infrastructure and application that serve as the interface between businesses and consumers. We now have over 167,000 customers, billions of consumer profiles, and hundreds of billions of customer messages and follow-on conversion data. We have a big opportunity to build state-of-the-art AI and machine learning technologies at Klaviyo to power our products and develop AI agents that can automatically create and execute marketing or customer experiences, strategies, and campaigns for any business.

As a Sr. AI Engineer at Klaviyo, you'll play a key role in designing and building scalable backend systems and user experiences that power our AI products and AI agent solutions. You'll partner closely with product managers, machine learning engineers, and data scientists, to drive real-world impact at scale. This is a backend-heavy role with opportunities to influence architecture, async processing pipelines, distributed systems, and more.

• Design and build backend systems that support scaling our AI solutions for 167K+ customers.
• Develop robust, reliable and scalable data collection and processing pipelines for machine learning models to train and consume.
• Develop robust, reliable and scalable services to serve AI models in production environments.
• Contribute to evolving our agentic architecture — making our AI agents more self-sufficient and performant.
• Contribute to a culture of ownership, experimentation, and customer-centric product thinking.

• 5–7 years of professional experience in software engineering, with a strong focus on backend systems and distributed architectures.
• Have hands-on experience building and deploying generative AI and agentic AI applications into production, with expertise in prompt engineering, few-shot learning, fine tuning and evaluation.
• Experienced backend engineer with a strong track record of building scalable, distributed systems, especially in the service of AI agent capabilities.
• Proficient in Python and modern backend frameworks (FastAPI, Django preferred).
• Experience creating human and automated evals to ensure high AI model quality.
• Proficient in big data tools such as Apache Spark and Hadoop.
• Deep experience with asynchronous processing and distributed task queues (Celery, Kafka, SQS, RabbitMQ, Redis).
• Strong understanding of database technologies and ORMs (SQLAlchemy, Alembic).
• Comfortable with cloud-native architectures (AWS) and container orchestration (Kubernetes); can manage infrastructure and CI/CD pipelines.
• Skilled at designing and building robust APIs.
• Able to operate with a high degree of autonomy, handle ambiguity, and thrive in a fast-moving, startup-like environment.
• Driven by curiosity. You're someone who learns and stays up to date with this rapidly evolving field.
• Comfortable collaborating directly with product managers and customers to shape solutions.

• Trained ML models in the past and deployed them in production systems to generate impact to businesses.
• Experience in reinforcement learning.

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 ), instant messaging platforms, or unsolicited calls.

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