Software Engineer, Agent Runtime

About Us

Sierra is the leading platform for customer-facing AI agents, working with many of the world's biggest brands — including The GAP, Rocket Mortgage, SoFi, Sutter Health, and SoftBank — to transform how they serve customers and grow their businesses. We are primarily an in-person company based in San Francisco, with growing offices across North America, Europe, and Asia.

What You'll Do

• Build the core systems that power agents: Work on the Agent SDK — the orchestration engine, runtime, and primitives that define how agents reason, take actions, and interact with users and systems.
• Design the agentic loop: Help define how agents operate in real-world environments with primitives that are steerable, verifiable, conversational, and adaptive.
• Improve retrieval and grounding: Build systems that ensure agents provide accurate, trustworthy responses by effectively retrieving and using knowledge.
• Build evaluation systems: Design frameworks that measure and improve agent quality over time for Sierra and its customers.

What You'll Bring

• A passion for being on the frontier of AI products.
• Strong software engineering fundamentals and experience building production systems.
• Motivation and high-agency to drive outcomes in a high-autonomy culture.
• 4+ years hands-on experience building production products and systems.
• Degree in Computer Science or related field, or equivalent professional experience.

Even Better

• Experience building AI-powered systems or agent frameworks.
• Experience with retrieval, evaluation systems, or LLM-based applications.
• Experience building developer platforms or SDKs.
• Experience with Go and TypeScript.