Senior Backend Engineer - Agent Runtime & AI Workflows

The Briefed; Boston (MA); On-site; USD 140,000 - 210,000; Full time

Job summary

Klaviyo is seeking a Senior Software Engineer for the Agent Runtime & Customer Workflows to design scalable backend systems and AI-driven experiences that enable autonomous agents to reason, retrieve context, execute tools, and perform multi-step actions for customers.

You will work on agentic infrastructure, evaluation frameworks, and production guardrails, partnering with customers and cross-functional teams to deliver reliable scalable AI capabilities.

Qualifications

• 5–7 years of professional software engineering experience with backend systems and distributed cloud applications.
• Hands-on experience deploying generative AI or agentic AI applications into production.

Responsibilities

• Design and build reliable, high-throughput backend services and APIs powering AI-driven customer workflows.
• Address applied AI challenges across RAG, context grounding, model selection, and hallucination mitigation.
• Develop automated and human-in-the-loop evaluation strategies and production metrics.
• Implement production guardrails, fallbacks, retry logic, observability, and failure-handling mechanisms.
• Build asynchronous and distributed workflows capable of processing high-volume AI workloads.
• Collaborate with external customers, product managers, and cross-functional teams to translate feedback into production solutions.
• Participate in on-call rotations to diagnose and mitigate production incidents.

Skills

Python

FastAPI

Django

Asynchronous processing

Distributed queues

AWS

Kubernetes

REST/gRPC

CI/CD pipelines

Databases

Tools

Celery

Kafka

AWS SQS

RabbitMQ

Redis

Docker

Kubernetes

Job description

Klaviyo is seeking a Senior Software Engineer for the Agent Runtime & Customer Workflows to design scalable backend systems and AI-driven experiences that enable autonomous agents to reason, retrieve context, execute tools, and perform multi-step actions for customers.

You will work on agentic infrastructure, evaluation frameworks, and production guardrails, partnering with customers and cross-functional teams to deliver reliable scalable AI capabilities.