AI Phone - Senior Agent Runtime Engineer

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.