Software Engineer - Agent Harness
$478,400–$478,400 year
HybridSan Francisco, California, United States
Job Summary
Architect the next-generation execution runtime for the Agent Harness, building reliable state machines that manage agent trajectories, memory retention, and tool-execution loops. Design and scale highly secure, isolated environments using Docker, gVisor, or WebAssembly to safely execute agent-generated code without risking host infrastructure. Build high-throughput APIs and integration layers connecting the platform to external services, databases, and web search utilities while engineering robust system-level guardrails against prompt injection and jailbreak attempts. Implement advanced routing, context pruning, and caching strategies to optimize LLM token usage and minimize round-trip latencies. Write comprehensive high-level design documents, align cross-functional teams on the technical roadmap, and mentor senior and mid-level engineers. This Staff AI Engineer role requires 6+ years of experience in distributed systems and 2+ years in production agent execution environments, with expertise in Go, Python, and runtime isolation technologies.
Required Qualifications
- Minimum 6+ years of professional software engineering experience
- Proven track record of designing, scaling, and operating mission-critical distributed systems
- 2+ years of production experience building or modifying agent execution environments, LLM orchestrators, or tool-calling frameworks
- Expert proficiency in Go
- Expert proficiency in Python
- Pragmatic, deep understanding of concurrent programming
- Deep understanding of microservices
- Deep understanding of gRPC
- Deep understanding of highly scalable API design
- Strong experience with containerization and virtualization technologies
- Solid grasp of sandboxing untrusted code execution
- Deep familiarity with message brokers
- Deep familiarity with caching infrastructure
- Deep familiarity with relational database design
- Deep familiarity with non-relational database design
- Bachelor's or Master's degree in Computer Science, engineering, or equivalent practical systems engineering experience
- Must be able to lift 50 lbs
Desired Qualifications
- Prior experience developing developer tools, SDKs, or extensible plug-in architectures
- Experience with frontend integration (React, TypeScript) to support human-in-the-loop debugging interfaces or agent visual builders
- Experience working in high-growth, fast-paced startup environments
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