Harper
Senior Member of Technical Staff, Harness Engineering
San Francisco · Staff+
Sponsorship not specified$187k-$264kDetected 50 days ago
LLMsAgentic AILogisticsCommunication
About the role
- The loop, the tools, the memory, the execution environment, the guardrails, the fallback path, the observability - that's what decides whether an agent can actually do useful work inside a real company.
- That's the harness, and at Harper every agent (product and coding) rides on a shared one.
- If the harness is brittle, every pod ships brittle agents; if it's good, pod engineers stop rebuilding the same scaffolding and start shipping agents in days instead of weeks.
Responsibilities
- Build agent-loop primitives. Prompt construction, tool routing, retry/timeout/budget logic, multi-step orchestration.
- Own the tool layer for your domains. Schema, auth, rate-limit, observability per tool - tools other engineers build on.
- Eat your own dog food. You write code with our harness daily and feel every rough edge before anyone else reports it.
- You think in tool design, not just prompt design, and can describe a tool-design or sandbox decision you'd still defend in three years.
- You write code with AI daily and manage 3+ parallel sessions.
- Build agent-loop primitives.
- Almost no one joins Harper for insurance; they join to build the company that replaces how it works.
- sandbox/isolation infrastructure; open-source agent-framework contributions; foundation-model partner or early-access experience.
- The harness is infrastructure other engineers build their work on, so the bar is high and the blast radius is real - when you get it right, the whole org's agent velocity moves; when you don't, everyone feels it.
Requirements
- 3-6 years building software, with production agentic systems behind you (real users, real traffic - not demos) and experience with at least one major agent framework.
- Production agent/LLM systems experience: agent loops, tool integration, prompt engineering at scale.
Nice to have
- sandbox/isolation infrastructure
- open-source agent-framework contributions
- when you don't, everyone feels it.
- The right person wants that leverage and that pace.
Compensation
- $187,000-$264,000 cash (base + target performance bonus), plus competitive equity.
Benefits
- Uber commuter benefits; breakfast, lunch, and dinner provided; snacks and coffee stocked; free gym membership; health, dental, and vision.
- Bonus: sandbox/isolation infrastructure
Company info
- That makes the harness the company-specific leverage behind the whole bet - the model is replaceable, the substrate beneath it is the moat.
- We're not bolting AI onto insurance - we're rebuilding the entire business as software, on a simple bet: turning expert human judgment into compute is one of the largest transitions left to make, and a trillion-dollar industry still run 90% by hand is the place to prove it.
This listing is sourced directly from Harper's careers page and normalized into a canonical job model.