Senior Commercial Underwriter, Underwriting Intelligence

About the role

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: A routing rule at Harper can move thousands of accounts. If the risk judgment behind it is vague, unsupported, or wrong, scale multiplies the mistake. Great underwriting judgment exists — it's just trapped in individual inboxes, one-off decisions, messy submissions, and tribal knowledge, most of all in specialty commercial and E&S, where risk moves through PDFs, ACORDs, loss runs, supplementals, and broker notes that may or may not answer what an underwriter needs to know. You make that judgment explicit, source-backed, and safe to apply at scale. This is Harper's in-house underwriting encyclopedia, not an underwriting desk. You do not approve or decline individual accounts. You do not own market selection, the submission narrative, negotiation, or