Software Engineer, Agent Runtime — Build AI Agent SDKs

ContentBuffer; San Francisco (CA); On-site; USD 120,000 - 180,000; Full time

Benefits offered by this job

Flexible PTO

Medical, dental, and vision benefits

Life insurance and disability benefits

Retirement plan

Parental leave

Fertility and family building benefits

Lunch, snacks and beverages

Discretionary benefit stipend

Free alphorn lessons

Job summary

Sierra is seeking a Software Engineer for the Agent Runtime in San Francisco, CA. You will build core systems powering AI agents, design the agent loop, and improve retrieval and grounding for trustworthy responses.

This in-person role emphasizes production-grade engineering and autonomy in a fast-moving team. Ideal candidates have 4+ years of hands-on experience, a CS degree or equivalent, and familiarity with Go and TypeScript.

Qualifications

• Strong software engineering fundamentals and experience building production systems.
• 4+ years hands-on experience building production products and systems.
• Experience with Go and TypeScript is a plus.

Responsibilities

• Build the core systems that power agents using the Agent SDK.
• Design the agentic loop and define how agents operate in real-world environments.
• Improve retrieval and grounding to ensure accurate, trustworthy responses.
• Build evaluation frameworks to measure and improve agent quality over time.

Skills

Production systems

Software engineering

Go

TypeScript

Education

BS in CS or related field

Equivalent professional experience

Job description

Sierra is seeking a Software Engineer for the Agent Runtime in San Francisco, CA. You will build core systems powering AI agents, design the agent loop, and improve retrieval and grounding for trustworthy responses.

This in-person role emphasizes production-grade engineering and autonomy in a fast-moving team. Ideal candidates have 4+ years of hands-on experience, a CS degree or equivalent, and familiarity with Go and TypeScript.