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Salary: USD 116,000 - 174,000 / annual
Klaviyo is seeking a Software Engineer to join the Customer Agent team, building AI-native conversational products and agent workflows. You will design and develop scalable backend systems and AI-powered product experiences that enable agents to retrieve context, use tools, and take reliable action on behalf of customers.
This is a backend-heavy role with opportunities to contribute to user-facing experiences. You will independently own meaningful pieces of larger systems, contribute to technical decisions, and develop depth across backend engineering, applied AI, and production reliability.
Key responsibilities include:
- Build and improve reliable backend systems and APIs powering AI-driven customer experiences
- Develop production agentic features involving tool use, context management, retrieval, structured outputs, orchestration, and multi-step workflows
- Solve applied AI problems across retrieval and RAG, grounding, hallucination mitigation, model selection, and choosing between LLM-based, deterministic, or hybrid approaches
- Build evaluation approaches including representative datasets, automated and human evaluation, regression testing, qualitative error analysis, and production signals
- Improve system reliability through guardrails, retries, fallbacks, observability, monitoring, and thoughtful failure handling
- Build asynchronous and distributed processing workflows supporting AI workloads at scale
- Participate in on-call rotation and help diagnose, mitigate, and learn from production incidents
- Work with external customers and cross-functional partners to understand workflows, identify pain points, and translate feedback into product improvements
- Monitor shipped experiences and use quality metrics, system performance, and customer feedback to guide iteration
Klaviyo serves more than 167,000 customers and processes billions of consumer profiles, messages, interactions, and conversion signals, creating a unique opportunity to build state-of-the-art AI systems at scale.
REQUIREMENTS:
- 3+ years of professional software engineering experience, with experience building backend systems or distributed applications
- Hands-on experience building or contributing to generative AI or agentic AI applications, ideally used by real users or in production environments
- Proficiency in Python and experience with modern backend frameworks such as FastAPI or Django
- Experience with asynchronous processing or distributed task/event systems such as Celery, Kafka, SQS, RabbitMQ, or Redis
- Working knowledge of databases, data modeling, APIs, and persistence patterns used in production systems
- Comfort working in cloud environments with experience in AWS, containers, Kubernetes, infrastructure automation, or CI/CD systems
- Ability to reason about tradeoffs among quality, latency, cost, reliability, and implementation complexity
- Comfort working through ambiguity, breaking larger problems into smaller pieces, and making progress without every requirement being fully specified
- Experience with, or strong interest in, working directly with external customers to understand problems and improve products
- Motivation to ship useful, reliable products and deepen engineering judgment in a rapidly evolving technical space
NICE TO HAVE:
- Experience training, fine-tuning, distilling, or otherwise adapting machine learning or language models
- Experience with reinforcement learning or feedback-driven optimization
- Experience with evaluation infrastructure such as LLM-as-judge systems, evaluator calibration, benchmark datasets, or AI quality tooling
- Experience operating AI systems at meaningful production scale or optimizing inference cost, latency, or throughput
