Senior Software Engineer, Agent PlatformAt 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 Senior Software Engineer, Agent Platform, you'll play a key role in designing and scaling the backend systems that power our AI products and agent solutions. This backend-heavy role gives you opportunities to influence architecture, async processing, and distributed systems.
You'll collaborate closely with product managers, ML engineers, and data scientists to deliver real-world impact at scale.This role is hybrid and based in Boston.How you'll make a difference:Design and build backend systems to scale AI solutions for 167K+ customers.Contribute to our agentic architecture to support performant AI agents.Build tools to tune LLM-based features, deploy agents, MCP and RAG in production, and evaluate performance using tools like Arize, OpenAI, Bedrock, LangChain, vLLM and Ray.Develop reliable, scalable data pipelines and APIs for AI systems.Foster a culture of ownership, experimentation, and customer-first thinking.Who you are:5+ years of experience as a backend software engineer, building scalable, distributed systems.Strong experience working in production environments and launching ML/AI projects.Hands-on experience with generative AI and agentic AI applications in production.Proficient in Python (or similar).Comfortable collaborating with cross-functional technical partners.Curious, proactive, and eager to learn.Nice to have:Experience with big data tools (e.g., Apache Spark, Ray).Familiarity with cloud infrastructure (AWS, Terraform, Kubernetes).Knowledge of ML frameworks (Huggingface, PyTorch, TensorFlow, Keras).Base Pay Range For US Locations: $148,000 — $222,000 USDThis role may require up to 10% travel for purposes such as new hire onboarding, client or partner work if applicable, team meetings, and industry events. Travel is coordinated in advance.Get to know KlaviyoWe'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.By participating in Klaviyo's interview process, you acknowledge that you have read, understood, and will adhere to our Guidelines for using AI in the Klaviyo interview Process. For more information about how we process your personal data, see our Job Applicant Privacy Notice.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.
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