Ben Shi

Research at Sierra

Ben is on the Research team at Sierra. Previously, he was at Princeton University and Meta.

Posts

Announcement · March 2026 sierra.ai ↗

τ³-Bench: Advancing Agent Benchmarking to Knowledge and Voice

τ³-bench extends the benchmark family with the τ-knowledge and τ-voice tracks, advancing agent evaluation to unstructured knowledge and real-time voice.

Victor Barres, Ben Shi, Ola Zytek, Soham Ray, Keshav Dhandhania & Pedram Razavi

Research · February 2026

τ-knowledge

A benchmark for evaluating AI agents in knowledge-intensive customer support: a realistic fintech knowledge base of 698 documents paired with tasks requiring multi-step reasoning, policy application, and tool use.

Ben Shi, Ola Zytek & Pedram Razavi

Engineering · February 2026

τ³-Bench: Fixing Airline + Retail

We audited and fixed 50+ tasks across the airline and retail domains, addressing incorrect expected actions, ambiguous instructions, impossible constraints, and missing fallback behaviors.

Victor Barres & Ben Shi