Sierra

We’ve built a transcription platform that dynamically routes across providers, incorporates a customer’s context, supports 70+ languages, and adapts to real-world variability, improving both agent effectiveness and customer satisfaction.

𝜏-Knowledge measures how well agents can work through messy, evolving knowledge bases to complete complex, multi-step tasks. While models are improving, they still struggle to reliably use this information in practice, leaving a large gap to real-world performance.

Material Event filed 2026-05-11

Sierra's always-on evaluation layer use an LLM-as-judge to review every conversation so businesses can track agent quality and customer sentiment. But who evaluates the monitors?

Quarterly Report filed 2026-05-07

Getting LLMs the right context, at the right time, is the central challenge in building sophisticated, real-world agents. The solution: Context engineering.

We’re raising $950 million from new and existing investors, at a valuation of over $15 billion.

𝜏-voice is a benchmark for real-time voice agents on 278 grounded customer-service tasks across retail, airline, and telecom. It pairs deterministic, end-to-end task scoring with realistic, controllable audio — diverse personas, environmental noise, and free-form turn-taking.

We are excited to announce the acquisition of Paris-based Fragment, which helps businesses scale their operations using AI, freeing up employees to focus on higher value work.

We’ve redesigned our engineering interview process from the ground up.

Proxy Statement filed 2026-04-21