Lead Software Engineer, AI Email App

About the Role There are over 5 billion users using basic applications today such email, notes, tasks, calendar and they're not AI-native. Our mission is to build proactive applications for anyone in the world, who are not used to complex prompting. We aim to bring intelligence to conversations, errands, organising and workflows, with minimal to no prompting. Our first application is an agent-first mobile communication app. We believe building applications that users use daily for communication, coordination and collaboration needs will help integrate AI into their lives. The net effect is to eliminate misinformation, achieve low coordination costs, enable high quality tasks and collaboration at scale with minimal or little prompting. As Lead Software Engineer, AI Email Apps, you own the engineering layer that turns AI capability into a reliable product. You will shape the architecture across backend services, APIs, and client applications, while leading a small team of senior engineers. This is a hands-on leadership role. You stay close to the code, make critical architectural decisions, and ensure the system remains fast, reliable, and coherent as it scales. What You'll Own Own the application engineering strategy and execution across backend, mobile, and desktop. Design reliable systems for AI-powered workflows, including state, orchestration, tool use, retries, fallbacks, and failure handling. Build the APIs and abstractions that connect AI systems to real-world product e