AI Phone - Senior Agent Runtime Engineer

About the role

About We are reimagining the phone. AI phones need to be proactive, intuitive, intelligent and low cost. This is a mission critical for rest of the world to adopt intelligence. There are over 5 billion people using everyday applications such as email, messaging, notes, tasks, and calendars, yet most are not AI-native. Our mission is to build proactive applications and devices that bring intelligence into daily conversations, coordination and workflows, with minimal prompting. Focus: Building the actual execution infrastructure for AI agents. Responsibilities • Implement agent runtime and orchestration components. • Build tool-calling and execution interfaces. • Support multi-step and long-running task execution. • Manage task state, execution history and asynchronous workflows. • Implement error handling, retries and recovery mechanisms. • Integrate multiple model providers. • Build observability and tracing for agent execution. • Optimize latency, reliability and inference costs. • Work with context and memory components to provide relevant information to agents. Requirements • Strong backend engineering experience. • Experience with distributed systems and asynchronous workflows. • Experience integrating LLMs into production applications. • Strong API and service architecture knowledge. • Experience with queues, state management and observability. • Good understanding of tool calling and structured outputs. Nice to have • Production agent framework or custom agent runtime experience. • Experience with Temporal or similar workflow orchestration systems. • Experience with model routing and inference optimization. • Experience with AI evaluation and tracing.

Posted Nov 6, 2026