SeniorMemberofTechnicalStaff,HarnessEngineering

SENIOR MEMBER OF TECHNICAL STAFF, HARNESS ENGINEERING Harper is an AI-native commercial insurance company in San Francisco. 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. We've grown ~100x in the last year and we move at that speed — on-site, in person, long days, very high standards. Almost no one joins Harper for insurance; they join to build the company that replaces how it works. THE ROLE The model is only one part of a worker. 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. That makes the harness the company-specific leverage behind the whole bet — the model is replaceable, the substrate beneath it is the moat. You'll build inside the harness layer — the meta-harness wrapping our frontier coding agents, OpenClaw, Hermes, and our internal agents — working alongside the engineer setting harness direction, shipping the primitives every agent team depends on. WHAT YOU'LL DO - Build agent-loop primitives. Prompt construction, tool routing, retry/timeout/budget logic, multi-step orchestration. - Ship execution-environment infra. Sandbox lifecycle, isolation, blast-radius limits, filesystem and network policy for agents. - Own the tool layer for your domains. Schema, auth, rate-limit, observability per tool — tools other engineers build on. - Wire model-provider routing. Provider fallback chains, eval-driven model selection, cost/l