Rowan Stone is a technology executive and entrepreneur with more than 20 years of experience across engineering and emerging technology.

He is the CEO and co-founder of Sapien, where he works on infrastructure for verifying AI-generated work. He previously held leadership roles at Coinbase and worked on Base, its Layer 2 network. ^[1]​

Career

Stone transitioned into the cryptocurrency industry in 2016 when he founded Alterchain Ltd., a company that provides computing power for mining major cryptocurrencies, including Ethereum, Litecoin, Bitcoin, and Horizen.

In 2017, he joined Horizen, initially leading its UK operations. He was subsequently promoted to Director of Business Development and later became Director of Operations and Business Development, where he oversaw the regional expansion efforts of the blockchain platform.

In 2020, Stone took on several roles in the decentralized finance (DeFi) and venture capital sectors. He co-founded AstroTools, a DeFi dashboard created to connect and aggregate data from both centralized and decentralized exchanges. During the same year, he served as Chief Operating Officer at Totle, a decentralized exchange aggregator. He also joined Horizen Labs, the commercial arm of Horizen, as Vice President of Business Development before transitioning to an advisory role. Additionally, he became the Managing Director at Launch Code Capital, a firm focused on investments in early-stage technology companies.

From 2021 to 2024, Stone held multiple leadership positions at Coinbase. A company he had previously co-founded was sold to Coinbase. ^[4] His roles at the cryptocurrency exchange included Director of Onchain Business Development, Head of Crypto, and Head of Business and Operations for Base, Coinbase's Layer-2 network. His work involved leading initiatives in DeFi, gaming, non-fungible tokens (NFTs), stablecoins, and tokenization.

In 2024, Stone joined Sapien as its Chief Business Development Officer. Later that year, he was appointed CEO, a position he holds as a co-founder of the company. ^[2]​

Interviews

AI and Human Data

In an August 2025 interview on the An Hour of Innovation podcast, Stone outlined his transition from Scotland’s energy industry into crypto, blockchain mining, and early DeFi, before focusing on AI data quality. He described Sapien as a decentralized data factory that links enterprises with global contributors who monetize their knowledge by completing tasks ranging from simple to highly specialized, with accuracy requirements varying from approximately 80% to over 99%, depending on the model's needs.

Stone discussed how contributor performance influences task progression, how diverse contributors help mitigate dataset bias shaped by customer requirements, and how the platform utilizes cryptocurrency to simplify cross-border payments.

He concluded by noting that while AI may reduce the need for certain forms of expert input, human judgment will remain essential for navigating randomness and real-world interactions in AI systems. ^[5]​

AI Development

In a July 2025 interview on The BlockHash Podcast, Stone discussed his transition from the energy and engineering sector into cryptocurrency mining, eventually finding his focus in decentralized AI.

He described Sapien’s mission as creating a system where individuals can monetize their knowledge while supplying enterprises with accurate, human-sourced data for specialized AI models, addressing problems that arise when synthetic data replaces human input.

Stone outlined Sapien’s token-collateral incentive structure, its reputation-based quality monitoring, and the platform’s range of accessible task formats, including voice and image work.

He also emphasized how a global contributor base helps mitigate bias, noted that some models may require intentional bias depending on context, and discussed the growing importance of decentralized data sourcing in future AI development, concluding with upcoming platform updates designed to support an expanding user base. ^[3]​

Pay-to-Train AI

In a June 2025 interview on the Block By Block Show, Stone discussed his path from Coinbase—where he previously sold a company—to co-founding Sapien, noting that his experience there reinforced the need for products that give users tangible reasons to adopt on-chain technology.

He described Sapien’s goal of training AI with expert human feedback through a decentralized workforce that can monetize its nuanced knowledge, supported by gamified features designed to make data labeling more engaging.

Stone highlighted Sapien’s customer base of 27 clients, including Fortune 100 companies such as Amazon and Toyota, with a focus on 3D and 4D data annotation, and explained quality controls that rely on staked collateral and reputation to unlock higher-value tasks.

He highlighted the growing demand for accurate AI data, the platform’s cooperative stance toward competitors, upcoming plans for a token generation event to broaden participation, and real-world results, including helping a tutoring company transition into an AI-driven education platform. ^[4]​

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