Email Infrastructure Engineer

About primitive.dev primitive.dev is building the communication layer for the agent economy. As AI agents increasingly act on behalf of people and businesses, companies need infrastructure to identify them, understand what they need, and interact with them at scale. We rebuilt email from the ground up for machine-to-machine communication, optimizing the entire stack for latency, throughput, reliability, and developer experience. On top of that infrastructure, we deploy and operate agents for our customers. They begin as a general interface to the business, then learn from incoming traffic and create specialized agents to handle recurring workflows. What you'll do Build the infrastructure that makes primitive.dev a full-scale email service provider. You will work across bare metal, Kubernetes, and the mail stack to build systems capable of moving billions of agent messages quickly and reliably. This role spans distributed systems, networking, SMTP, queues, deliverability, reputation, and abuse. What you bring You have deep experience with Kubernetes, Linux, networking, and production infrastructure You understand email systems, including SMTP, MTAs, queues, or deliverability You are as comfortable writing production software as operating production infrastructure Nice to have Experience operating high-volume email or messaging systems Experience with bare-metal infrastructure or Rust Former founder Compensation $190k-$230k base salary plus equity. World-class benefits. Full-time and in person in San Francisco, relocation fully covered if needed. Visa: US citizen/visa only.