Sandstone Raises $30M Series A Led by Lightspeed to Build the Legal Department of the Future

Investment will accelerate scaling, community building, and expand access to Sandstone's Legal Relationship Management platform for in-house legal teams

NEW YORK, NY — June 9, 2026 — Sandstone, the platform for managing every legal relationship, today announced it has closed $30 million in Series A financing led by Lightspeed Venture Partners, with participation from existing investors from the January seed round, including Mantis VC, SV Angel, Operator Partners, Kearny Jackson, Daybreak Ventures, Litquidity Ventures, and others. The round marks a pivotal milestone for the company as it accelerates product development and expands its platform to empower a new generation of AI-native legal departments.

Legal has historically operated across a fragmented collection of contracts, emails, tickets, and institutional memory. Sandstone brings those fragments together into a single platform, connecting counterparties, stakeholders, matters, obligations, contracts, and history into one working surface for legal teams. With legal context unified, teams can deploy AI across intake, triage, drafting, review, and knowledge retrieval with a complete understanding of the relationship behind the work. Where legacy tools like CLMs fragment work across disconnected applications, Sandstone unifies it, turning legal from a process bottleneck into a strategic partner.

The investment follows Sandstone's $10 million seed round led by Sequoia in January 2026 and reflects the company's rapid traction among in-house legal teams seeking a better way to operate. In the past 90 days, Sandstone has grown revenue by over 40x and onboarded customers like Wayfair, Hypertherm, Grindr, Mercury, MasterClass, Cox Media, and ElevenLabs, spanning industries from e-commerce to media to fintech. The company has also launched major product milestones — validating the market's demand for a unified platform that manages the full spectrum of legal relationships,beyond fragmented point solutions.

"We built Sandstone because in-house legal teams have been underserved by software for too long. The work, context, and history behind every decision are scattered across contracts, emails, tickets, and institutional memory. We're bringing those pieces together into a single place where legal can operate with complete context. This funding from Lightspeed gives us the fuel to expand capabilities and bring the legal department of the future to every company that needs it."

— Nick Fleisher, CEO and Co-Founder, Sandstone

Lightspeed's investment reflects industry conviction in vertical AI — purpose-built platforms that embed deeply into a profession's workflows rather than offering generic automation. Sandstone's approach, training AI on legal-specific context and integrating directly with how in-house teams actually work, positions it as a uniquely defensible platform in an underserved category.

"The best vertical AI companies win because they understand the profession as deeply as the technology. Sandstone has demonstrated that rare combination — a team that has lived these problems firsthand and the engineering ambition to solve them at scale. We believe Sandstone is building the defining platform for in-house legal."

— Guru Chahal, Partner, Lightspeed Venture Partners

The Series A will support three strategic priorities: scaling customer success infrastructure to support rapid enterprise onboarding, hiring top talent across all functions, and expanding Sandstone's community efforts for in-house legal professionals.

About Sandstone

Sandstone was born out of the acute frustration experienced by in-house legal teams who spend more time on process than progress due to fragmentation across disparate business systems. The platform provides a comprehensive solution for intake, triage, execution, fulfillment, and measurement of legal work — designed to run across email, messaging, and the business tools teams already use. Sandstone is headquartered in New York. To learn more, visit www.sandstone.com

MEDIA CONTACT

Maggie Pote

Head of Growth Marketing

press@sandstone.com

248-892-8333