Tethered: Our Agents Are Us — Shu Fang, Two Sigma
Sep 3, 2026 · 21:10
Two Sigma's Shu Fang explains why every employee at the 25-year-old quant fund runs a cloud agent as themselves, not a service account — echoing the doubles in the film Us. A separate agent identity collapses fast: permissions drift, licensing doubles, and systems like Google Workspace refuse two identities on the same data. Agents instead run in per-person Kubernetes namespaces built for automated jobs, with a sidecar mounting the identity into the pod. Since agent and human share one identity, a header propagated like a trace ID recovers not just the actor but the replayable chain behind a result. For web access, they use Google's web grounding for enterprise — an index inside their network boundary — and deny native search and fetch tools, trading freshness (about 24 hours) for removing exfiltration and prompt injection risk.
