Cartesia

Cartesia is a San Francisco AI company founded in 2023 by Stanford AI Lab PhDs who invented State Space Models (SSMs) — a faster, more compute-efficient alternative to the transformer architecture powering most large language models. The company builds and sells real-time voice AI through an API and developer platform. Its core products are Sonic (text-to-speech), Ink (speech-to-text), and Line (a platform for building voice agents end-to-end). The key differentiator is ultra-low latency — Sonic runs at ~45ms, roughly half the industry norm — enabling natural, real-time spoken conversation rather than stilted, laggy responses. Customers are developers and enterprises who embed Cartesia's models into phone support bots, digital avatars, recruiting agents, gaming NPCs, and healthcare tools. Notable enterprise customers include ServiceNow, Quora, Cresta, Decagon, and VAPI. Revenue is primarily API consumption-based, with enterprise contracts growing.

$200M valuation · 142 employees · 33 open roles

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Cartesia

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