Principal Software Engineer, AI Email App

About the role

The company builds proactive, agent-first mobile applications that bring AI to everyday communication, coordination and collaboration with minimal prompting. As Principal Software Engineer for the AI email app, you own the engineering layer that turns AI capability into a reliable product, shaping the architecture across backend services, APIs and client applications while leading a small team of senior engineers. It is a hands-on leadership role.

Key responsibilities

• 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 experiences.
• Lead a small, senior engineering team through design reviews, code reviews and hands-on mentorship.
• Make trade-offs across latency, reliability, cost, security and user experience.
• Establish observability, monitoring, testing and operational excellence.
• Partner with ML leadership to turn model capabilities into shippable products.

Required profile

• Significant experience leading application or product engineering for complex systems.
• Strong hands-on background building and shipping production backend systems.
• Experience building AI-powered products that integrate with modern ML/LLM capabilities.
• Strong technical judgment and comfort making decisions with incomplete information.
• Comfortable across backend and client platforms, with deep expertise in at least one.
• Bias toward ownership, shipping and learning from real-world usage, with high standards for code quality and reliability.

Applications are evaluated by the technical team, and interviews (3 to 4, virtual and/or onsite) are scheduled promptly after a fit is found.